vim-lsc: init at fe6d3bd

`natebosch/vim-lsc` is a language server client plugin for vim/neovim. This commit
adds it to the `vim-plugin-names` file and the generated vim-plugins
file.

This is a reboot of #52407 that doesn't call the `update.py` script for
vim plugins, because doing so led to quick merge conflicts. Let me know
if there is a preferred way to do this.