minor: create convention commit syntax

[jtuglu1]

Description

Something I've seen many large open source projects adopt:

1. Conventional commit syntax (easier to auto-generate release notes, bisect for issues, etc. as it requires more context to be stored in the commits themselves, and not the PR/issue).

Release note

Enforce conventional commit format. This will also help making debugging issues, etc. as in addition to GH tags (something not persisted in the git lineage) breaking changes/bug fixes/feature information is recorded in the git tree.

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This PR has:

• been self-reviewed.
  • using the concurrency checklist (Remove this item if the PR doesn't have any relation to concurrency.)
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.

[jtuglu1]

@gianm updated. I think we should also make the default repo settings on PRs to do a merge and take the PR description (e.g. not just force a *-list of commit messages (which often aren't descriptive at all).