Shell prompt cwd with 2-3 parts with special git handling

[bew]

This CWD formatting should be available in all major shell, and editors if needed.
(IDEA: make a Rust impl usable everywhere? or re-impl everywhere?)

2-3 parts:

• By default, path is split and only last 2 items are kept: …/nested/dir
• When the 3rd last item is $HOME, put ~ instead of …
• When the 3rd last item is a Windows drive, put that drive (C:\) instead of …

Examples

Given:

• mybar is a named dir pointing to /foo/bar
• deeper is a named dir pointing to /foo/bar/somewhere/deeper
• myrepo is a named dir pointing to /path/to/reponame

Arbitrary path

When in /foo/bar/baz:
Show: ~mybar

When in /foo/bar/baz:
Show: ~mybar/baz

When in /foo/bar/deep/baz:
Show: …/bar/baz (?or ~mybar (bmark)/deep/baz?)

When in /path/to/somewhere:
Show: …/to/somewhere

When in /foo/bar/somewhere/deeper/in/nested/baz:
Show: ~deeper/baz (and NOT ~mybar …/nested/baz)

Git repos

When inside a git repo, show the repo name followed by the last 2 path items.
The repo name should be colored differently from the rest of the path items (with a bg color? customizable?).

MAYBE: Actually I could do this also for named directories 🤔
where the persistent part is the alias for named dir, and the remaining of the path is put on the side 👀

When (git) is mentioned here, it should be replaced by a git icon.

When in /path/to/reponame:
Show: ~myrepo (git)

When in /path/to/other-repo:
Show: …/to/other-repo (git)

When in /path/to/reponame/in/nested:
Show: ~myrepo (git)/in/nested

When in /path/to/reponame/in/nested/dir:
Show: ~myrepo (git)…/in/nested

When in /path/to/other-repo/in/nested:
Show: …/to/other-repo (git)/in/nested