Updated PyLSP lua source

[gerazov]

It's convenient to have this info in the configurations docs.

Fixes #1880

[lithammer]

Wouldn't it be better to just link to https://github.com/python-lsp/python-lsp-server/blob/develop/CONFIGURATION.md? Trying to duplicate the information available upstream but in a "nvim-lspconfig way" is going to turn into a maintenance nightmare.

[gerazov]

Like I mentioned in #1880 for me it was not apparent how to configure pylsp from the nvim init.lua from reading https://github.com/python-lsp/python-lsp-server/blob/develop/CONFIGURATION.md where lspconfig points to.

I think having just the three examples here could help people, especially since turning off mccabe and E501 is something that they might want to do right away. I didn't mean to have it be exhaustive by any means.

[justinmk]

Wouldn't it be better to just link to https://github.com/python-lsp/python-lsp-server/blob/develop/CONFIGURATION.md? Trying to duplicate the information available upstream but in a "nvim-lspconfig way" is going to turn into a maintenance nightmare.

+1