Merge #2370

2370: Add note about neovim's built in language server r=matklad a=norcalli

I implemented a builtin language server client (`:h lsp.txt`) for neovim and it's been in master since 2019-11-13. We built https://github.com/neovim/nvim-lsp to contain easy configuration settings for servers which we hope to be a database that can be referenced for other editors/3rd party users as well.

Support will be merged very soon https://github.com/neovim/nvim-lsp/pull/43.

Co-authored-by: Ashkan Kiani <ashkan.k.kiani@gmail.com>