Ensure Single Copy of Release Notes

[djbrooke]

What this PR does / why we need it:

We're in a state right now where we maintain two copies of our release notes - one in Github.com/iqss/dataverse/releases and one in the /docs folder. This isn't great, because if there are changes needed, people could make them in one of two places and they could fall out of sync. This PR makes documentation changes that will result in the single, post-release source of truth being the release notes in the github.com/iqss/dataverse/releases - any edits or additions would go there.

Which issue(s) this PR closes:

Closes #7988

Special notes for your reviewer:

Suggestions on how to test this:

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

Is there a release notes update needed for this change?:

Additional documentation:

[pdurbin]

I left a comment.

[pdurbin]

@scolapasta this is the line I mentioned in standup that we might want to think about. That is, when does it make sense to remove the combined release note file from git?

I think of "merge develop into master" as the final step before a release with regard to commits. And since the release note file is temporary, we should probably remove it before this final step.

[pdurbin]

Just testing approval automation (not an actual approval).

[pdurbin]

Closing. There are merge conflicts because we merged PR #8877 which updates the "Making Releases" page. There was enough of a rewrite of that page that we should simply make a new PR to address #7988 some day.

I agree with where this PR was going. That is, let's only have one version of the release notes, the "live" version, rather than saving .md files in git.