.github: add a "Contribution Guidelines" to the pull request template

[ljflores]

These guidelines refer contributors to the "Submitting Patches to Ceph" doc
and the "Submitting Patches to Ceph - Backports" doc. Even though there are
already tips for titling/signing commits in the PR template, these tips
are commented out and easy to gloss over once the contributor creates the
PR. These existing tips do not include any pointers about staging backports.

Fixes: https://tracker.ceph.com/issues/55418
Signed-off-by: Laura Flores lflores@redhat.com

Checklist

• Tracker (select at least one)
  • References tracker ticket
  • Very recent bug; references commit where it was introduced
  • New feature (ticket optional)
  • Doc update (no ticket needed)
  • Code cleanup (no ticket needed)
• Component impact
  • Affects Dashboard, opened tracker ticket
  • Affects Orchestrator, opened tracker ticket
  • No impact that needs to be tracked
• Documentation (select at least one)
  • Updates relevant documentation
  • No doc update is appropriate
• Tests (select at least one)
  • Includes unit test(s)
  • Includes integration test(s)
  • Includes bug reproducer
  • No tests

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[ljflores]

@djgalloway I've noticed that some new contributors are still unsure about the commit/backport workflow. Not sure if you have any opinions on this suggestion, but let me know if it seems reasonable.

[ljflores]

jenkins test make check

[djgalloway]

Isn't this sort of just a repeat of line 21?

[ljflores]

Yeah, it is somewhat a repeat. However, line 21 is commented out, and many people miss it when they go to create their PR. The link in the comment is also not clickable. My suggestion is to move the link out the comment so that people are more likely to take notice of the link.

IMO these lines make sense to keep in comment form:

ceph/.github/pull_request_template.md

Lines 6 to 19 in c60a9c7

	- Please give your pull request a title like
	[component]: [short description]
	- Please use this format for each git commit message:
	[component]: [short description]
	[A longer multiline description]
	Fixes: [ticket URL on tracker.ceph.com, create one if necessary]
	Signed-off-by: [Your Name] <[your email]>
	For examples, use "git log".

But this should be removed and housed under the "Contribution Guidelines" section:

ceph/.github/pull_request_template.md

Line 21 in c60a9c7

- The Signed-off-by line in every git commit is important; see <span class="x x-first x-last">[Submitting Patches to Ceph](https://github.com/ceph/ceph/blob/master/</span>SubmittingPatches.rst<span class="x x-first x-last">)</span>

[djgalloway]

Ah, I didn't know it was commented out.