## Summary
This is unfortunately longer than what we had, but I thought that this
section could use some clarification. In particular, newer syntactic
features can not appear in `sys.version_info` branches, they will always
lead to errors.
## Summary
The file is `cli.md`, not `commands.md`.
Not sure if there was an incomplete intention to rename the file here,
but for the moment I'm just fixing the link; renaming the file will
require adjusting at least the release script and possibly changing it
in the ruff repo as well.
## Test Plan
On this branch, the link works.
Moves most of the documentation into a dedicated `docs/README` to make
it easier to reach important content in the top-level readme like
"getting involved".
There are some minor changes to the heading levels here and link
changes, but otherwise the content is the same. Don't go deep on the
getting started section, that's changing in #329
