docs: release template: update based on 1.28 learnings

[BigLep]

This takes release issue changes and observations from #12109 with also having an eye towards the upcoming release process changes per #12072 .

The general goals here are:

1. Have a checkbox step for each step a releae engineer should take.
2. Reduce duplication in the template itself. Where content should be duplicated, there is a comment for the issue creator to handle the copy/pasting.

Checklist

Before you mark the PR ready for review, please make sure that:

• Commits have a clear commit message.
• PR title is in the form of of <PR type>: <area>: <change being made>
  • example: fix: mempool: Introduce a cache for valid signatures
  • PR type: fix, feat, build, chore, ci, docs, perf, refactor, revert, style, test
  • area, e.g. api, chain, state, mempool, multisig, networking, paych, proving, sealing, wallet, deps
• Update CHANGELOG.md or signal that this change does not need it.
  • If the PR affects users (e.g., new feature, bug fix, system requirements change), update the CHANGELOG.md and add details to the UNRELEASED section.
  • If the change does not require a CHANGELOG.md entry, do one of the following:
    • Add [skip changelog] to the PR title
    • Add the label skip/changelog to the PR
• Tests exist for new functionality or change in behavior
• CI is green

[BigLep]

This is a self-review to adjust some fixes and also to leave comments for reviewers like @rjan90 .

[BigLep]

@rjan90 : this is a proposed set of changes that I'm thinking would be good to land before copy/pasting in to #12343

[BigLep]

@rjan90 : in terms of terminology, are we going to say "Lotus Node" or "Lotus Client"? I think my release template update goes with "Lotus Node" (aligning with NodeBuildVersion), but I'm noticing #12072 talks about "Lotus Client" and I also see that in the title in #12157