Wrote new I2C topic.

docs/reference/pins/i2c-write-number.md

@@ -0,0 +1,32 @@
+# I2C Write Number
+
+Write the specified number to the specified 7-bit I2C address in the
+specified number format.
+
+```sig
+pins.i2cWriteNumber(0, 0, NumberFormat.Int8LE);
+```
+
+### Parameters
+
+* ``address``: the 7-bit I2C address to which to send ``value``
+* ``value``: the number to send to ``address``
+* ``format``: the number format for ``value``. Formats include
+  **Int8LE**, **UInt8LE**, **Int16LE**, **UInt16LE**, **Int32LE**,
+  **Int8BE**, **UInt8BE**, **Int16BE**, **UInt16BE**, and
+  **Int32BE**.
+  * **Int** stands for "integer", and **UInt** stands for "unsigned integer".
+  * **LE** stands for "little-endian" and **BE** stands for "big-endian".
+  * The number in each format name stands for the number of bits in the format.
+
+### Example
+
+The following example sends the value `2055` to the 7-bit I2C
+address `32` in big-endian 32-bit integer format.
+
+```blocks
+pins.i2cWriteNumber(32, 2055, NumberFormat.Int32BE);
+```
+### See also
+
+[I2C](https://en.wikipedia.org/wiki/I%C2%B2C)