重构：拆分配置文件

repos/.vitepress/config/nav.ts

@@ -0,0 +1,19 @@
+import type { DefaultTheme } from 'vitepress'
+
+export const nav: DefaultTheme.Config['nav'] = [
+  {
+    text: 'Bug万象集',
+    link: '/issues/index',
+    activeMatch: '/issues/' // 当前页面处于匹配路径下时, 对应导航菜单将突出显示
+  },
+  {
+    text: '"杂碎"逆袭史',
+    link: '/fragments/index',
+    activeMatch: '/fragments/'
+  },
+  {
+    text: '关于知识库',
+    link: '/about/index',
+    activeMatch: '/about/',
+  }
+]