Local release workflow

[tingerrr]

Currently, the release workflow is used to publish the package to typst/packages.

I propose changing it to be named publish and add a new workflow called release which actually handles the release on the repo itself.

This new workflow should either:

• on push of a tag matching v*: create a new draft release, or
• on creation of a release, upload release artifacts to a release page.

In either case, such an action should do a few things:

• Generate a default changelog from either a CHANGELOG.md file or the main git commit history
  • Although GitHub can do the latter for you, so this might not be too important.
• Compile and package supplementary material for a release, like manuals and other assets.
  • There's no hard rule on how documentation is done for Typst packages yet, most people simply compile a manual, some others like cetz host their own GitHub Pages, we could look at popular packages and adapt some of their practices.

[jamesrswift]

I agree that splitting publishing and releasing into separate commands would be beneficial - too many times have I botched a release and needed to manually clean up branches and tags, when it could have been averted by splitting the process