Move lsp config to local file structure

.config/nvim/lsp/stylelint_lsp.lua

@@ -0,0 +1,55 @@
+---@brief
+---
+--- https://github.com/bmatcuk/stylelint-lsp
+---
+--- `stylelint-lsp` can be installed via `npm`:
+---
+--- ```sh
+--- npm i -g stylelint-lsp
+--- ```
+---
+--- Can be configured by passing a `settings.stylelintplus` object to vim.lsp.config('stylelint_lsp'):
+---
+--- ```lua
+--- vim.lsp.config('stylelint_lsp', {
+---   settings = {
+---     stylelintplus = {
+---       -- see available options in stylelint-lsp documentation
+---     }
+---   }
+--- })
+--- ```
+
+local util = require 'lspconfig.util'
+
+local root_file = {
+  '.stylelintrc',
+  '.stylelintrc.mjs',
+  '.stylelintrc.cjs',
+  '.stylelintrc.js',
+  '.stylelintrc.json',
+  '.stylelintrc.yaml',
+  '.stylelintrc.yml',
+  'stylelint.config.mjs',
+  'stylelint.config.cjs',
+  'stylelint.config.js',
+}
+
+root_file = util.insert_package_json(root_file, 'stylelint')
+
+---@type vim.lsp.Config
+return {
+  cmd = { 'stylelint-lsp', '--stdio' },
+  filetypes = {
+    'astro',
+    'css',
+    'html',
+    'less',
+    'scss',
+    'sugarss',
+    'vue',
+    'wxss',
+  },
+  root_markers = root_file,
+  settings = {},
+}