Docs: Update issue templates to ask for PRs

[nzakas]

What is the purpose of this pull request? (put an "X" next to item)

[x] Documentation update
[ ] Bug fix (template)
[ ] New rule (template)
[ ] Changes an existing rule (template)
[ ] Add autofixing to a rule
[ ] Add a CLI option
[ ] Add something to the core
[ ] Other, please explain:

What changes did you make? (Give an overview)

Added a question to each issue template asking if the person creating the issue is willing to implement the change they are requesting. I thought at one point we had this, and I think it's a good way to nudge people into contributing rather than just expecting that someone else will implement the suggestion.

Is there anything you'd like reviewers to focus on?

Nothing in particular.

[not-an-aardvark]

Bikeshed: Could we reword this to something like "Would you be willing to submit a pull request" rather than "Will you submit a pull request"? It seems like the current wording might be interpreted as a request that someone work on a PR as soon as they create the issue, without waiting for feedback. People often report intended behavior as a bug if they misunderstand how it's supposed to work, and in those cases I wouldn't want them to preemptively spend their time on a PR only to be told later that the current behavior is correct.

[nzakas]

Fair point. I'd prefer to use "Are you willing..." instead of "Would you be willing..." as the latter is a bit more passive than I'm comfortable with. I'll make that change.

[platinumazure]

LGTM, thanks!

Nitpick: There is an inconsistent number of blank lines following the new question across the templates. But that's not a blocker.