Fix some titles, sigs in ref docs (#2128)

* Fix some title and sigs in ref docs

* better buffer source

docs/reference/serial/write-buffer.md

@@ -16,7 +16,7 @@ You place your data characters into an existing buffer. All of the data, the len
 
 Read some characters of data from a device connected to the I2C pins. Write the data to the serial port.
 
-```blocks
+```typescript
 pins.i2cWriteNumber(132, NumberFormat.UInt8LE, 0);
 let i2cBuffer = pins.i2cReadBuffer(132, 16, false);
 serial.writeBuffer(i2cBuffer);