Move lsp config to local file structure

.config/nvim/lsp/nginx_language_server.lua

@@ -0,0 +1,16 @@
+---@brief
+---
+--- https://pypi.org/project/nginx-language-server/
+---
+--- `nginx-language-server` can be installed via pip:
+---
+--- ```sh
+--- pip install -U nginx-language-server
+--- ```
+
+---@type vim.lsp.Config
+return {
+  cmd = { 'nginx-language-server' },
+  filetypes = { 'nginx' },
+  root_markers = { 'nginx.conf', '.git' },
+}