[docs] Lack of information about $_GET, $_POST, $_REQUEST, $_COOKIE, and $_SESSION variables

[jboulen]

What is the URL of the page?

https://moodledev.io/general/development/process/peer-review#syntax

What is the issue with this page?

Documentation indicates:

$_GET, $_POST, $_REQUEST, $_COOKIE, and $_SESSION are never used.

But nowhere documentation explains what to do instead.
For $_GET, $_POST and $_REQUEST, we can probably refer to this page.

Also, maybe some superglobals are missing in this list (eg: $_FILES and $_ENV).

Are you able to provide a patch for this?

None