DOC: add pre-release notes framework to docs

[tangkong]

Description

Adds pre-release notes stuff to the docs folder

Motivation and Context

I selfishly like doing pre-release notes so my name goes places. Also it feels weird to not have them at this point

Maybe I'll also add some actual contents to the docs page...

How Has This Been Tested?

I did a make html once

Where Has This Been Documented?

This is docs, but also this PR

Pre-merge checklist

• [x] Code works interactively
• [x] Code contains descriptive docstrings, including context and API
• [x] New/changed functions and methods are covered in the test suite where possible
• [x] Code has been checked for threading issues (no blocking tasks in GUI thread)
• [x] Test suite passes locally
• [x] Test suite passes on GitHub Actions
• [x] Ran docs/pre-release-notes.sh and created a pre-release documentation page
• [x] Pre-release docs include context, functional descriptions, and contributors as appropriate

[tangkong]

Whoops forgot to ask for a review here