previously disable the cache update was only possible on ubuntu
using the generic name wireguard_update_cache it can be enabled for all
operating systems
* add support for elementary OS
* update README
* add skip_ansible_lint for two tasks
* ignore two ansible-lint warnings for Raspbian Buster tasks
* update CHANGELOG
* update comment in defaults/main.yml and README
* Call Raspbian role only when Release is older than 11 (Bullseye)
* Rename raspbian-role to mark that it is intended for Buster and lower
Wireguard is directly supported by Raspbian 11 (Bullseye) and higher.
* Add a note regarding the scope of the Raspbian playbook