feat: add initial marko-js lsp config (#3228)

lua/lspconfig/configs/marko-js.lua

@@ -0,0 +1,21 @@
+local util = require 'lspconfig.util'
+
+return {
+  default_config = {
+    cmd = { 'marko-language-server', '--stdio' },
+    filetypes = { 'marko' },
+    root_dir = util.find_git_ancestor,
+  },
+  docs = {
+    description = [[
+      https://github.com/marko-js/language-server
+
+      Using the Language Server Protocol to improve Marko's developer experience.
+
+      Can be installed via npm:
+      ```
+      npm i -g @marko/language-server
+      ```
+    ]],
+  },
+}