chore: move release notes to main repository

[HonkingGoose]

Changes:

• Delete the release notes from this repository (the docs repo)
• Move the file to the main renovatebot/renovate repo with PR: https://github.com/renovatebot/renovate/pull/28721

Context:

We want to move the release notes to the main repository so that:

• we can update the release notes as we're working on a new major release
• more docs files are in the main repository

I'm marking this as a draft PR, until I can get some reviews and checks from you maintainers. I suspect I need to do more than just delete the release notes on the docs repository. 😄

[HonkingGoose]

I'm getting some shell check warnings. Not sure what those are about.

[viceice]

we should disable husky on CI and exclude those files from shellcheck

[HonkingGoose]

We moved the file to the main repository with this PR, that is now merged:

• https://github.com/renovatebot/renovate/pull/28721

So I think we can merge this, if we already pulled in a new Renovate submodule, that has the "moved" release notes in it? We don't want to accidentally have a broken link to the release notes because we're in-between the old situation and the new situation. :smile: