[redeboer]

• Closes Update developer instructions for prek and autofix.ci #313
• Closes Remove the fullscreen button from the documentation #320

Tip

Preview the updated developer guide.

📝 Documentation

• Replaced the "Pre-commit" section of docs/develop.md with a "Prek" section: installing prek with uv tool install prek, activating hooks with prek install --prepare-hooks, and running all checks with prek run -a. The old (pre-commit)= label is kept so that existing cross-references still resolve.
• Added a tip for developers coming from pre-commit on replacing the untracked Git hook shims, either by reinstalling them or with policy migrate, and on uninstalling pre-commit and pre-commit-uv.
• Documented the style task as a wrapper around prek run -a (with uv, Pixi, and prek tabs) and the upgrade task that runs prek autoupdate, and noted that the lock workflow bumps hook revisions the same way.
• Added an "autofix.ci" subsection that explains how style fixes are committed back to pull requests, why the workflow file must be named autofix.ci.yml, how forks and bot-authored commits are handled, and that the style workflow skips its own push job when autofix.ci is present.
• Replaced the pre-commit.ci badge in README.md with a prek badge.
• Removed the fullscreen button from the website header (use_fullscreen_button in docs/conf.py).
• Unwrapped hard-wrapped paragraphs in docs/develop.md.

Squash commit messages

* DOC: document the `style` and `upgrade` tasks
* DOC: explain how autofix.ci commits style fixes
* DOC: explain how to replace `pre-commit` Git hooks
* DOC: remove the fullscreen button
* DOC: replace pre-commit.ci badge with `prek` badge
* DOC: unwrap paragraphs in developer guide