Update WriteThePiCode.md

[BrahmaFarmsLLC]

Added option to capture the temprate in celsius or fahrenheit

[jimbobbennett]

This could be a useful change for US folks (only the US and a couple of small island nations use Fahrenheit, the majority of the world uses Celsius), but to avoid confusion the documentation would also need to be updated.

It would need:

• When the temperature units are set on the IoT Central interface, mention the user could also set the units to °F.
• Add a note to the section for the python code to mention the code possibilities to convert to °F

[BrahmaFarmsLLC]

I will add the changes and raise PR.