* update github bug template to have status:Unconfirmed
- by default, ensure that all new bugs are raised with the label status:Unconfirmed
- for the bug template where 'hints' exist - use HTML comments to hide these
* docs - update issue tracking
- convert from RST to markdown
- add details about when to use Github discussions instead of an issue
- add details about bugs will be raised with the status:Unconfirmed
- add link to PR triage guide
- add links to release schedule & roadmap
- put less emphasis on milestones for new issue creation