treesitter: add rainbow brackets

lua/plugins/treesitter.lua

@@ -5,6 +5,7 @@ return {
     'nvim-treesitter/nvim-treesitter-textobjects',
     'nvim-treesitter/nvim-treesitter-context',
     'nvim-treesitter/nvim-treesitter-refactor',
+    'mrjones2014/nvim-ts-rainbow',
   },
   config = function()
     pcall(require('nvim-treesitter.install').update { with_sync = true })
@@ -29,6 +30,11 @@ return {
           node_decremental = '<C-Bslash>',
         },
       },
+      -- rainbow
+      rainbow = {
+        enable = true,
+        extended_mode = true,
+      },
       -- refactor
       refactor = {
         highlight_definitions = { enable = true, clear_on_cursor_move = true },