New category for discussion board: Rule Explaination

[IronTooch]

I think it would be super helpful to have a new section in the discussion board to explain why a rule was implemented, or what the net effect of it is. For new Ansible devotees, they may get a linting error, and not quite understand why the error is a big deal. Having more experienced or knowledgeable developers be able to explain why a rule was implemented in plain language would be super handy. This doesn't quite seem to fit in any particular category in the current discussion board.

The general idea would be that each topic would be literally just the name of the rule (e.g. Truthy,or package-latest), and questions about that specific implementation of the rule could be asked there.

I know it's fairly well documented on the Read the Docs, but sometimes the answer there is more obscure, or is not mentioned at all, so this provides a place for Ansible Engineers to ask pointed questions.

E.g. A new Junior IaC engineer gets "command-instead-of-shell", and would like to know WHY they should use command instead of shell? What is the actual impact of using the full shell? This would be the place where someone could show a playbook demonstrating the real impact.

Inspired by discussion at #1903