refactor: 重构Neovim配置结构并更新文档

- 调整配置文件组织方式，新增init.lua作为入口
- 更新lazy-lock.json同步插件版本
- 完善lua/目录下的插件和配置模块结构
- 修改README.md补充配置说明和使用指南

lua/plugins/treesitter.lua

@@ -0,0 +1,17 @@
+return {
+	"nvim-treesitter/nvim-treesitter",
+	build = ":TSUpdate",
+	config = function()
+		require("nvim-treesitter.configs").setup({
+			ensure_installed = { "vim", "lua", "javascript", "typescript", "python", "html", "css", "markdown" },
+			sync_install = false,
+			auto_install = true,
+			highlight = {
+				enable = true,
+				additional_vim_regex_highlighting = false,
+			},
+			indent = { enable = true },
+		})
+	end,
+	event = "BufReadPost",
+}