[Docs] Writing a new Arduino documentation about GPIO

[halyssonJr]

Summary:

Writing a new Arduino documentation about GPIO

Impact:

None

@pedrominatel

[pedrominatel]

Thanks, @halyssonJr for taking this task!

Please, follow the same format and style as the other libraries. You can use as reference:

https://docs.espressif.com/projects/arduino-esp32/en/latest/api/i2c.html
and
https://docs.espressif.com/projects/arduino-esp32/en/latest/api/wifi.html

[halyssonJr]

Ok, @pedrominatel.

[halyssonJr]

@pedrominatel, submit PR #5894 !

[pedrominatel]

Please, fix the issues on this PR that I already mentioned there.

[VojtechBartoska]

Closing as PR was merged already.