This PR should remove all Headstart Annotations from themes in this repo.
Why? Headstart annotations stored in WP.com themes are generated, tested, and sent for translation via WP-CLI scripts running on subversion-ed WordPress sandboxes. I recently updated Headstart annotations for our 20+ recent themes in order to correct some issues in our FSE Plugin and Page Layout feature. When discussing how to get these annotations updated in this themes repo @michaeldcain and came up with two options.
1. Copy-paste back into the affected themes in this repo.
2. Just remove all the Headstart annotations from this repo.
The second option seemed the simplest. It leaves **all** Headstart annotations on WP.com "ignore-able" for this GH repo and reduces the chance of Headstart annotations becoming out of date in this GH repo, potentially reducing future errors.
* Update selectors for button blocks, for better custom colour fallbacks.
* Update drop cap size, to scale when font size does.
* Add visited states to custom colours.
* Position bullets inside of lists when widget blocks are centred.
* Reorganize styles a bit, consolidate header styles, and delete empty selectors
* Update editor colour palette to match theme's colours
* Remove styles for pre and code blocks in editor; doesn't look identical to the front-end but they blocked the text from being edited
