Enable GitHub Discussions for questions

[shakuzen]

While we sometimes answer Micrometer usage questions in GitHub issues, it would be better to do so in a dedicated place. Stackoverflow and Slack are both existing options, which we encourage users to use. GitHub has recently released "Discussions" as a beta feature that can be enabled.

I am proposing we enable Discussions but limit its usage to questions for now. This keeps GitHub issues focused on actionable changes to be made in this repository, while still allowing questions that can be converted to an issue if appropriate. Questions opened as issues can be moved to Discussions, as well, from my understanding. Having a Discussions board may also encourage community members to participate in answering questions more so than when questions are opened as GitHub issues.

Tasks:

• Enable Discussions
• Update support policy