Add alternative ways to install python-lsp-server

[nougcat]

Currently in main README file, the only way listed to install it is - through pip, which is probably fine way, but it would be great to see more clean and elegant ways to install it, like through official linux repos (for example fedora, debian/deb-based OSes or arch), or maybe some people on windows can install it using conda

If i can get a permission, i can also write it myself and submit it as PR.

[ccordoba12]

Hey @nougcat, thanks for interest in wanting to help us improve our docs. You don't need write permissions to do it, simply create a fork and send us a pull request with your changes.

[jgarte]

@nougcat Can also be installed with GNU/Guix

[nougcat]

@jgarte It is also available in opensuse, solus and others, but package for it is named everywhere the same (except for alpine). So i think that it only makes sens to show installation instruction only for the biggest distros, so readme won't become unnecessarily long