Make example config more easy to read

Ref https://github.com/nvim-treesitter/nvim-treesitter/issues/2095#issuecomment-992759818

doc/nvim-treesitter.txt

@@ -40,11 +40,27 @@ To enable supported features, put this in your `init.vim` file:
 >
   lua <<EOF
   require'nvim-treesitter.configs'.setup {
-    ensure_installed = "maintained", -- one of "all", "maintained" (parsers with maintainers), or a list of languages
-    ignore_install = { "javascript" }, -- List of parsers to ignore installing
+    -- One of "all", "maintained" (parsers with maintainers), or a list of languages
+    ensure_installed = "maintained",
+
+    -- Install languages synchronously (only applied to `ensure_installed`)
+    sync_install = false,
+
+    -- List of parsers to ignore installing
+    ignore_install = { "javascript" },
+
     highlight = {
-      enable = true,              -- false will disable the whole extension
-      disable = { "c", "rust" },  -- list of language that will be disabled
+      -- `false` will disable the whole extension
+      enable = true,
+
+      -- list of language that will be disabled
+      disable = { "c", "rust" },
+
+      -- Setting this to true will run `:h syntax` and tree-sitter at the same time.
+      -- Set this to `true` if you depend on 'syntax' being enabled (like for indentation).
+      -- Using this option may slow down your editor, and you may see some duplicate highlights.
+      -- Instead of true it can also be a list of languages
+      additional_vim_regex_highlighting = false,
     },
   }
   EOF