[doc] Install via uv

Seems like uv is a popular choice to deploy and manage projet. Notably the commande uv venv --python 3.11 makes it really easy to install the proper version of python without relying on the OS version...

uv venv --python=3.11
uv pip install pglift[cli]
source .venv/bin/activate

The pipx install command can be replaced by

uv tool install pglift-cli --with pglift

And it's even possible to run pglift on-the-fly with uvx:

uvx --from pglift-cli pglift --help