DOC: split the http-request actions in their own section

DOC: split the http-request actions in their own section

Since http-request was first introduced, more and more actions have been
added over time. This makes the "http-request" difficult to read and some
actions were forgotten in the list.

This is an attempt to make the documenation cleaner. In future steps, it
would be great to provide at least one example for each action.