Add a section about neovim's default LSP client

[HighCommander4]

These days, neovim has a built-in LSP client, and many users using clangd with neovim seem to be using that rather than coc-clangd or YouCompleteMe.

Similar to #90, it would be great if someone familiar with this client could document how to do things like get clangd logs when using this client.

[HighCommander4]

Making note of instructions for getting clangd logs which were posted in the Discord channel:

You can get the path with :lua print(vim.lsp.get_log_path()) in command mode in any nvim instance, and you probably need to set your log level wherever you're starting the the LSP with vim.lsp.set_log_level("DEBUG") (you can probably run that the same as above in command mode, but, I haven't tried it.)

I think a lot of users use https://github.com/neovim/nvim-lspconfig, though, and there are examples there for configuring servers including passing args to the server when it's started. If you’re using lspconfig you can see the logs with :LspLog

[HighCommander4]

And additional details about how specify clangd arguments like --log=verbose if not using lspconfig:

In init.lua, or wherever they're configuring, and assumes clangd is in their path (can probably provide an absolute path as well):

vim.lsp.start({
  name = 'clangd',
  cmd = {'clangd', '--log=verbose'}, -- I think that is the correct clangd flag
  root_dir = vim.fs.dirname(vim.fs.find({'compile_commands.json'}, { upward = true })[1]), -- This bit may not be needed for clangd, but, maybe nvim-lsp needs it, too.
})

[HighCommander4]

I think a lot of users use https://github.com/neovim/nvim-lspconfig, though, and there are examples there for configuring servers including passing args to the server when it's started.

Documenting the nvim-lspconfig steps more explicitly for my own reference:

1. Open ~/.config/nvim/init.lua
2. Add a section like this (or if it's already present then add the desired arguments to cmd):

   local lspconfig = require('lspconfig')
   lspconfig.clangd.setup({
     name = 'clangd',
     cmd = {'/path/to/clangd', '--log=verbose'}
   })   

[fannheyward]

Should be closed by #103 too, cc @HighCommander4

[HighCommander4]

I'm going to reopen this because information about how to obtain clangd logs is not included yet in the section about neovim's LSP client, and this is something that users still ask about fairly regularly.