Update pull request template user-facing changes instructions

[tashima42]

Proposed Changes

Updates the Pull Request template User-Facing change section to include a standard for how it should be written.

Types of Changes

Doc update

Verification

Testing

Linked Issues

rancher/ecm-distro-tools#219

User-Facing Change

Further Comments

[brandond]

Can we keep the note about NONE, assuming that still prevents the PR from showing up in the release notes?

Suggested change

	Each change should be in a new line;
	The first character of each line must be a letter;
	If the PR requires additional action from users switching to the new release, include the string "action required";
	Each change note should be on a line by itself.
	Each change note should be a complete sentence, starting with a capitalized word and ending with punctuation.
	If the change requires additional action from users switching to the new release, include the string "action required" in the note.
	If the change has no user impact or should otherwise be hidden from the release notes, use the bare word NONE as the note.

[tashima42]

Most PRs don't adhere to this, and some write it outside the block or a different text. The gen_release_notes command will ignore the block if it's empty, so I think it makes sense to remove it, here are some examples:
#7873, #7872, #7858, #7839, #7834, #7833, #7827, #7805, #7777, #7776, #7259, #7153, #6998

[briandowns]

I think it's easier for all involved to have a literal nothing than a word to indicate nothing. Less complicated tooling then.

[brandond]

The current behavior is for the tool to use the PR title instead of the note if there is no note, right? This for compatibility with RKE2 where we don't have a note section in the PR template.

If we wanted to change the behavior to omit the PR from the release notes if there is no note (making omission the default, instead of opted into by using the literal string NONE as the note), that'd be fine by me.

[tashima42]

The current behavior, is that we include all the PR titles, plus a list of the changes described in the User-Facing release-note block. If the block is missing, empty or just "NONE", we just use the title. https://github.com/rancher/ecm-distro-tools/blob/77c9043241babf6b58f428344125ebdd7ea2f6c8/repository/repository.go#L308-L326

[brandond]

I believe we need some way to exclude things from the release notes. I don't have strong feelings on whether that is an opt-out, or opt-in, but the special handling for NONE was documented in the PR template and was intended as a way to prevent the release notes from being polluted with meaningless changes, such as pure CI/dev changes that do not have any impact on end users.