This PR adds some helper functions in the `ui` crate that can be used to
get textural representations of keystrokes or key bindings.
Release Notes:
- N/A
This PR adds a new `WithRemSize` element to the `ui` crate.
This element can be used to create an element tree that has a different
rem size than the base window.
`WithRemSize` can be nested, allowing for subtrees that have a different
rem size than their parent and their children.
<img width="912" alt="Screenshot 2024-05-16 at 2 25 28 PM"
src="https://github.com/zed-industries/zed/assets/1486634/f599cd9f-c101-496b-93e8-06e570fbf74f">
Release Notes:
- N/A
