[vim] Add treesitter plugin

Add after config script

config/nvim/after/plugin/treesitter.lua

@@ -0,0 +1,11 @@
+local treesitter_configs = require 'nvim-treesitter.configs'
+
+treesitter_configs.setup {
+    ensure_installed = { "lua", "vim", "javascript", "swift" },
+    sync_install = true,
+    auto_install = true,
+    hightlight = {
+        enable = true,
+        additional_vim_regex_highlighting = false,
+    },
+}