[actions] Create an action that comments on PRs when code affects documentation

[Daltz333]

Any code that has been referenced or included in frc-docs should have an associated documentation PR. We should create an action or CI that will

1. Grabs the current diff
2. Create a list of URLs that will then be matched with frc-docs source
3. Comment on the PR that the associated frc-docs line # has been affected and to update that line.

[Starlight220]

@Daltz333 isn't this solved by Inspector? Or could be fixed by one of #3069 / #3672?

I'm honestly not sure if it'll be that significant of a workflow improvement compared to the current setup with Inspector.

[Daltz333]

Inspector does not automatically update when code changes. This would be useful and push the burden to whoever updates the example, as it should be IMO.