Document Module Naming guidelines in the Docs

[DonGiovanni83]

Is your feature request related to a problem? Please describe.
As a developer, I need guidelines for naming the ansible modules in this collection in a consistent and intuitive manner, so that it is clear to developers as well as to users where to find certain features and functionalities of this collection.

Describe the solution you'd like
I suggest a Naming convention following the web UI menu structure. See Additional context for an example.

Describe alternatives you've considered
I have not considered alternative naming conventions, but I am open to suggestions. This convention must be documented in the doc site for developers.

Additional context
Let's take an example of a simple configuration. If we want to have a module that sets the hostname and domain of the firewall, I suggest naming that module system_settings_general because the hostname and domain would be configured in the menu at System>Settings>General as depicted in the following image:

This for example could translate to this ansible module:

- name: set fw hostname
  puzzle.opnsense.system_settings_general:
    hostname: "fw01"
    domain: "test.local"