Add API and HTTP requests Documentation (maybe for the Arduino IoT Cloud???)

Hello I love Arduino but I cloudn't find any documentation about API or HTTP requests in Arduino's Website. I found aRest but this is a project which is from Arduino's fan and not from the Arduino's Team. aRest is really good but is missing many things like change the variable value with an API request.

The issue does not name a repository file, test, or documentation entry point. First determine whether the requested material concerns the Arduino website, Arduino IoT Cloud, or aRest, then define the documentation scope; done requires an agreed scope and complete API/HTTP request documentation.

Written by the indexing model from the issue text.