Provide links to the documentation as part of the check output

[mrfoxtalbot]

Given that one of the main goals of this plugin is to allow plugin authors to self-review, I propose that each individual check includes a link to the documentation:

We found [foo] problem on line N You can see how to fix this [foo] issue in this doc [Link to doc]

Ideally, every single check should include a link to the documentation where it is explained/addressed.

[mrfoxtalbot]

Noting that this is probably the relevant place but currently the information is very limited. We should expand that documentation to account for other common mistakes.