pxt-microbit Accessibility PR (#529)

* Accessibility changes

docs/reference/radio/on-data-packet-received.md

@@ -8,13 +8,13 @@ Run part of a program when the @boardname@ receives a
 radio.onDataPacketReceived(({receivedNumber, receivedString, time, serial, signal}) => { });
 ```
 
-### ~hint
+## ~hint
 
 To add or remove the parts of the packet from the block, try clicking the blue gear in the corner!
 
-### ~
+## ~
 
-### Callback Parameters
+## Callback Parameters
 
 * ``packet`` - the [packet](/reference/radio/packet) that was received by the radio. The packet has the following properties:
   * `receivedNumber` - The [number](/types/number) that was sent in this packet or `0` if this packet did not contain a number. See [send number](/reference/radio/send-number) and [send value](/reference/radio/send-value)
@@ -23,7 +23,7 @@ To add or remove the parts of the packet from the block, try clicking the blue g
   * `serial` - The serial number of the @boardname@ that sent this packet or `0` if the @boardname@ did not include its serial number.
   * `signal` - How strong the radio signal is from `-128` (weak) to `-42` (strong).
 
-### Example
+## Example
 
 This program keeps sending numbers that says how fast the @boardname@ is
 slowing down or speeding up.  It also receives numbers for the same
@@ -39,7 +39,7 @@ radio.onDataPacketReceived(({ receivedNumber }) => {
 })
 ```
 
-### Example
+## Example
 
 This program uses the signal strength from received packets to graph the
 approximate distance between two @boardname@s.
@@ -56,7 +56,7 @@ radio.onDataPacketReceived(({ signal, receivedNumber }) => {
 })
 ```
 
-### See also
+## See also
 
 [send number](/reference/radio/send-number),
 [send string](/reference/radio/send-string),

docs/reference/radio/on-data-received.md

@@ -10,7 +10,7 @@ Run part of a program when the @boardname@ receives a
 radio.onDataReceived(() => { });
 ```
 
-### Example
+## Example
 
 This program keeps sending numbers that says how fast the @boardname@ is
 slowing down or speeding up.  It also receives numbers for the same
@@ -26,7 +26,7 @@ radio.onDataReceived(() => {
 })
 ```
 
-### See also
+## See also
 
 [on data packet received](/reference/radio/on-data-packet-received),
 [send number](/reference/radio/send-number), [set group](/reference/radio/set-group)

docs/reference/radio/packet.md

@@ -10,7 +10,7 @@ A packet that was received by the radio.
 * `serial` - The serial number of the @boardname@ that sent this packet or `0` if the @boardname@ did not include its serial number.
 * `signal` - How strong the radio signal is from `255` (weak) to `0` (strong).
 
-### See also
+## See also
 
 [on data packet received](/reference/radio/on-data-packet-received),
 

docs/reference/radio/receive-number.md

@@ -8,11 +8,11 @@ Receives the next number sent by a @boardname@ in the same ``radio`` group.
 radio.receiveNumber();
 ```
 
-### Returns
+## Returns
 
 * the first  [number](/types/number) that the @boardname@ received. If it did not receive any numbers, this function will return `0`.
 
-### Example: Simple number receiver
+## Example: Simple number receiver
 
 This example receives the number broadcasted another @boardname@ and shows it
 as a bar graph.
@@ -23,7 +23,7 @@ radio.onDataReceived(() => {
 })
 ```
 
-### Example: Light level receiver
+## Example: Light level receiver
 
 This example shows the light level from the [light level sender example](/reference/radio/send-number)
 as a number.
@@ -36,7 +36,7 @@ basic.forever(() => {
 })
 ```
 
-### Example: Mailbot
+## Example: Mailbot
 
 This example receives the light level from the [light level sender example](/reference/radio/send-number)
 and shows a text string like **ALERT** if the light level becomes much brighter.
@@ -58,7 +58,7 @@ basic.forever(() => {
 })
 ```
 
-### See also
+## See also
 
 [send number](/reference/radio/send-number), [on data received](/reference/radio/on-data-received)
 

docs/reference/radio/receive-string.md

@@ -8,12 +8,12 @@ Find the next string sent by `radio` from another @boardname@.
 radio.receiveString()
 ```
 
-### Returns
+## Returns
 
 * the first [string](/types/string) that was sent. If no
   string was sent, then this function returns an empty (blank) string.
 
-### Example: Simple receiver
+## Example: Simple receiver
 
 Show the string sent by another @boardname@.
 
@@ -23,7 +23,7 @@ radio.onDataReceived(() => {
 });
 ```
 
-### Example: Two-way radio
+## Example: Two-way radio
 
 If you load this program onto two or more @boardname@s, you can send a code word from one of them to the others by pressing button `A`.
 The other @boardname@s will receive the code word and then show it.
@@ -39,13 +39,13 @@ radio.onDataReceived(() => {
 });
 ```
 
-### ~hint
+## ~hint
 
 A radio that can both transmit and receive is called a _transceiver_.
 
-### ~
+## ~
 
-### Example: Mood radio
+## Example: Mood radio
 
 This is a simple program to send whether you are happy or sad over ```radio```.
 Use the `A` or `B` button to select an emotion.
@@ -84,7 +84,7 @@ radio.onDataReceived(() => {
 });
 ```
 
-### See also
+## See also
 
 [send string](/reference/radio/send-string), [on data received](/reference/radio/on-data-received)
 

docs/reference/radio/received-signal-strength.md

@@ -14,16 +14,16 @@ it needs to run **receive number** first.
 radio.receivedSignalStrength();
 ```
 
-### Returns
+## Returns
 
 * a [number](/types/number) between `-128` and `-42` that means
 how strong the signal is.
 
-### Simulator
+## Simulator
 
 This function only works on the @boardname@, not in browsers.
 
-### Example
+## Example
 
 This example shows how strong the radio signal of the
 [light level sender example](/reference/radio/send-number) is.
@@ -37,7 +37,7 @@ basic.forever(() => {
 });
 ```
 
-### See also
+## See also
 
 [on data packet received](/reference/radio/on-data-packet-received), [send number](/reference/radio/send-number), [on data received](/reference/radio/on-data-received)
 

docs/reference/radio/send-number.md

@@ -6,12 +6,12 @@ Broadcast a [number](/types/number) to other @boardname@s connected via ``radio`
 radio.sendNumber(0);
 ```
 
-### Parameters
+## Parameters
 
 * ``value`` - a [number](/types/number) to send.
 
 
-### Example: Broadcasting acceleration
+## Example: Broadcasting acceleration
 
 This example broadcasts the value of your @boardname@'s ``acceleration``
 in the `x` direction (left and right) to other @boardname@s.  This kind
@@ -23,7 +23,7 @@ input.onButtonPressed(Button.A, () => {
 })
 ```
 
-### Light level sender
+## Light level sender
 
 This example broadcasts the level of the light around it.
 You can do some interesting things with it if you use it along with the
@@ -37,7 +37,7 @@ basic.forever(() => {
 })
 ```
 
-### See also
+## See also
 
 [on data packet received](/reference/radio/on-data-packet-received)
 

docs/reference/radio/send-string.md

@@ -7,12 +7,12 @@ maximum string length is 19 characters.
 radio.sendString("Hello!")
 ```
 
-### Parameters
+## Parameters
 
 * `msg` is a [string](/types/string) to send by radio.
 
 
-### Example: Two-way radio
+## Example: Two-way radio
 
 If you load this program onto two or more @boardname@s, you can send a
 code word from one of them to the others by pressing button `A`.  The
@@ -29,13 +29,13 @@ radio.onDataPacketReceived(({ receivedString }) => {
 });
 ```
 
-### ~hint
+## ~hint
 
 A radio that can both transmit and receive is called a _transceiver_.
 
-### ~
+## ~
 
-### See also
+## See also
 
 [on data packet received](/reference/radio/on-data-packet-received)
 

docs/reference/radio/send-value.md

@@ -7,12 +7,12 @@ The maximum [string]() length is 12 characters.
 radio.sendValue("name", 0);
 ```
 
-### Parameters
+## Parameters
 
 * ``name`` is a [string](/types/string) to send by radio
 * ``value`` a [number](/types/number) to send by radio
 
-### Example: Broadcasting acceleration
+## Example: Broadcasting acceleration
 
 This program sends your @boardname@'s **acceleration** (amount it is
 speeding up or slowing down) in the `x` direction (left and right) to
@@ -37,7 +37,7 @@ radio.onDataPacketReceived(({ receivedString, receivedNumber }) => {
 });
 ```
 
-### See also
+## See also
 
 [on data packet received](/reference/radio/on-data-packet-received)
 

docs/reference/radio/set-group.md

@@ -14,15 +14,15 @@ to talk to each other because they will have the same group ID.
 radio.setGroup(0);
 ```
 
-### Parameters
+## Parameters
 
 * ``id`` is a [number](/types/number) from ``0`` to ``255``.
 
-### Simulator
+## Simulator
 
 This function only works on the @boardname@, not in browsers.
 
-### Example
+## Example
 
 This program makes the group ID equal 128.
 
@@ -30,7 +30,7 @@ This program makes the group ID equal 128.
 radio.setGroup(128)
 ```
 
-### See also
+## See also
 
 [on data packet received](/reference/radio/on-data-packet-received),
 [send number](/reference/radio/send-number),

docs/reference/radio/set-transmit-power.md

@@ -12,22 +12,22 @@ measured as +4 dBm.
 radio.setTransmitPower(7);
 ```
 
-### Range
+## Range
 
 If your @boardname@ is sending with a strength of `7`, and you are in
 an open area without many other computers around, the @boardname@ signal
 can reach as far as 70 meters (about 230 feet).
 
-### Parameters
+## Parameters
 
 * ``power`` is a [number](/types/number) between ``0`` and ``7`` that
 means how strong the signal is.
 
-### Simulator
+## Simulator
 
 This function only works on the @boardname@, not in browsers.
 
-### Example
+## Example
 
 This program makes the ``radio`` send at full strength.
 
@@ -35,7 +35,7 @@ This program makes the ``radio`` send at full strength.
 radio.setTransmitPower(7)
 ```
 
-### See also
+## See also
 
 [on data packet received](/reference/radio/on-data-packet-received),
 [send number](/reference/radio/send-number),

docs/reference/radio/set-transmit-serial-number.md

@@ -6,11 +6,11 @@ Make the ``radio`` packet embed the board serial number with each packet of data
 radio.setTransmitSerialNumber(true);
 ```
 
-### Parameters
+## Parameters
 
 * ``transmit`` is a [boolean](/types/boolean) that represents whether the serial number needs to be transmitted.
 
-### Example
+## Example
 
 This program makes the ``radio`` send the serial number in each packet.
 
@@ -18,7 +18,7 @@ This program makes the ``radio`` send the serial number in each packet.
 radio.setTransmitSerialNumber(true);
 ```
 
-### See also
+## See also
 
 [on data packet received](/reference/radio/on-data-packet-received),
 [send number](/reference/radio/send-number),

docs/reference/radio/write-received-packet-to-serial.md

@@ -8,7 +8,7 @@ Should be called within a callback to
 radio.writeReceivedPacketToSerial();
 ```
 
-### Data received format
+## Data received format
 
 The format for received data printed to serial is as follows:
 
@@ -16,7 +16,7 @@ The format for received data printed to serial is as follows:
 - [send value](/reference/radio/send-value): ```{v:ValueSent,t:MicrobitTimeAlive,s:SerialNumber,n:"Name"}```
 - [send string](/reference/radio/send-string): ```{t:MicrobitTimeAlive,s:SerialNumber,n:"Text"}```
 
-### Examples
+## Examples
 
 When ```radio``` data is received (after pressing the ``A`` button on
 the second @boardname@), this program sends temperature data to
@@ -36,7 +36,7 @@ Sample output to serial when ``A`` button pressed:
 {v:27,t:323,s:0}
 ```
 
-### See also
+## See also
 
 [send number](/reference/radio/send-number),
 [send value](/reference/radio/send-value),

docs/reference/radio/write-value-to-serial.md

@@ -8,7 +8,7 @@ Writes the data received by ``radio`` to serial in JSON format.
 radio.writeValueToSerial();
 ```
 
-### Data received format
+## Data received format
 
 The format for received data printed to serial is as follows:
 
@@ -16,7 +16,7 @@ The format for received data printed to serial is as follows:
 - [send value](/reference/radio/send-value): ```{v:ValueSent,t:MicrobitTimeAlive,s:SerialNumber,n:"Name"}```
 - [send string](/reference/radio/send-string): ```{t:MicrobitTimeAlive,s:SerialNumber,n:"Text"}```
 
-### Examples
+## Examples
 
 When ```radio``` data is received (after pressing the ``A`` button on
 the second @boardname@), this program sends temperature data to
@@ -36,7 +36,7 @@ Sample output to serial when ``A`` button pressed:
 {v:27,t:323,s:0}
 ```
 
-### See also
+## See also
 
 [send number](/reference/radio/send-number),
 [send value](/reference/radio/send-value),