Idea: keyboard shortcuts for all text editor buttons

Right now, there are only some keyboard shortcuts for text edition on Basecamp (cmd+b for bold, cmd+i for italics, cmd+k for links, etc)

It would be fantastic if we could have keyboard shortcuts for other options such as:
- Title
- Quotes
- Highlights (this one is tricky since there are many sub options)
- Divider
- unordered list
- ordered list

Thanks!

Start by reviewing the existing keyboard-shortcut handling and text-editor buttons, then map the requested Title, Quotes, Highlights, Divider, unordered-list, and ordered-list actions. Resolve shortcut choices and the Highlights sub-options before implementation; done means each requested action has a clear, non-conflicting shortcut and the behavior is verified.

Written by the indexing model from the issue text.