doc fixes

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

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+# Set Transmit Serial Number
+
+Make the ``radio`` packet embed the board serial number with each packet of data.
+
+```sig
+radio.setTransmitSerialNumber(true);
+```
+
+### Parameters
+
+* ``transmit`` is a [boolean](/reference/types/boolean) that represents whether the serial number needs to be transmitted.
+
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
+### Example
+
+This program makes the ``radio`` send the serial number in each packet.
+
+```blocks
+radio.setTransmitSerialNumber(true);
+```
+
+### See also
+
+[receive number](/reference/radio/receive-number), [send number](/reference/radio/send-number), [on data received](/reference/radio/on-data-received)
+
+```package
+microbit-radio
+```