docs: 重构文档配置并添加邮箱提醒功能文档

- 将导航栏和侧边栏配置拆分为单独模块
- 添加邮箱提醒功能文档
- 优化文档配置结构，添加编辑链接和最后更新时间显示
- 从管理后台文档中移除邮箱配置内容，保持功能文档独立

docs/.vitepress/configs/nav.js

@@ -0,0 +1,5 @@
+export default [
+	{ text: '首页', link: '/' },
+	{ text: '部署文档', link: '/guide/backend-config' },
+	{ text: 'API 文档', link: '/api/overview' },
+];

docs/.vitepress/configs/sidebar.js

@@ -0,0 +1,26 @@
+export default [
+	{
+		text: '快速开始',
+		items: [
+			{ text: '项目介绍', link: '/guide/getting-started' },
+			{ text: '后端配置', link: '/guide/backend-config' },
+			{ text: '前端配置', link: '/guide/frontend-config' },
+		],
+	},
+	{
+		text: '功能',
+		items: [
+			{ text: '管理后台', link: '/function/admin-panel' },
+			{ text: '通知邮箱', link: '/function/email-reminder' },
+			{ text: '数据迁移', link: '/function/data-migration' },
+		],
+	},
+	{
+		text: 'API 文档',
+		items: [
+			{ text: '概览', link: '/api/overview' },
+			{ text: '公开 API', link: '/api/public' },
+			{ text: '管理员 API', link: '/api/admin' },
+		],
+	},
+];