Do not recommend `sudo pip`, at least on Linux

[alexpdp7]

Recent Debian versions refuse to install packages as root with pip. Recent Fedora versions display a big warning message (although they proceed by default). This is a good idea, because installing with root uses the system Python, and installing things with that can cause unintended side-effects.

(I'm not sure I would recommend this either on macOS, but I have less knowledge about that.)

I would recommend steering people towards distribution packages. Debian stable has a somewhat old version (well, the version that was out when Debian stable was released), but Fedora tracks closely pgcli.

If people want to install a newer version, I'd recommend pipx, which is packaged for common distros, or uvx.

I'm happy to send a PR editing the README if you let me know what you would prefer.

[j-bennet]

Hi @alexpdp7, feel free to send a PR. Some of our docs are quite outdated.

[alexpdp7]

Sent #1503. Feel free to close the issue even if the PR is not merged. Cheers!