Move lsp config to local file structure

.config/nvim/lsp/mutt_ls.lua

@@ -0,0 +1,17 @@
+---@brief
+---
+--- https://github.com/neomutt/mutt-language-server
+---
+--- A language server for (neo)mutt's muttrc. It can be installed via pip.
+---
+--- ```sh
+--- pip install mutt-language-server
+--- ```
+
+---@type vim.lsp.Config
+return {
+  cmd = { 'mutt-language-server' },
+  filetypes = { 'muttrc', 'neomuttrc' },
+  root_markers = { '.git' },
+  settings = {},
+}