CodeSniffer version update

Merge pull request #12 from wearenolte/update-view_item-format-string

* Update composer and PHP libraries
* Require PHP >=7.2 ore >=8.0
* Update 'view_item' format string, %S is not valid for sprintf.

Add PHP 8.0 support

• Update composer and PHP libraries
• Require PHP >=7.4 or >=8.0

Fix arguments being overwritten

Prevent the overwritten of the args by the default values instead.

Update on the docs

Update on the docs to match the new package name.

Update namespaces

Update from leean to lean namespace and package.

Fixes on class name

The previous version was not following PSR4 during the class definition of a new endpoint.