feat(lua/plugins): improve markdown-preview and treesitter setup

Enhancements:
- Refined markdown-preview configuration to use command toggles and lazy loading
- Simplified treesitter setup by using direct nvim-treesitter API

New Features:
- Added support for MarkdownPreviewStop command
- Updated ft configuration to use a table for markdown filetypes

Bug Fixes:
- None

lua/plugins/syntax.lua

@@ -6,7 +6,7 @@ return {
         build = ':TSUpdate',
         event = { 'BufReadPost', 'BufNewFile' },
         config = function()
-            require('nvim-treesitter.configs').setup({
+            require('nvim-treesitter').setup({
                 ensure_installed = require('config.extensions').ts_parsers,
                 auto_install = true,
                 highlight = {