Include all the available HTTP methods

[alvarobartt]

So as to create an API with all the available information, all the available HTTP methods should be presented with an example so that the user knows how do they all work.

Available HTTP methods on Flask RESTX APIs are: GET, POST, PUT, DELETE, PATH, OPTIONS and HEAD. Just like in Flask RESTPlus as specified at: https://flask-restplus.readthedocs.io/en/stable/swagger.html#documenting-the-methods