refine: 居中显示文档和演示地址

Author: wangchaoyangxi

src/pages/index/index.vue

@@ -18,7 +18,7 @@
     <view class="text-center text-4xl main-title-color mt-4">unibest</view>
     <view class="text-center text-2xl mt-2 mb-8">最好用的 uniapp 开发模板</view>
     <view class="text-justify max-w-100 m-auto text-4 indent mb-2">{{ description }} </view>
-    <view class="mt-8">
+    <view class="mt-8 text-center">
       <text class="text-green-400">在线文档：</text>
       <!-- #ifndef H5 -->
       https://codercup.github.io/unibest-docs/
@@ -29,7 +29,7 @@
       </a>
       <!-- #endif -->
     </view>
-    <view class="mt-4">
+    <view class="mt-4 text-center">
       <text class="text-green-400">在线预览：</text>
       <!-- #ifndef H5 -->
       https://codercup.github.io/unibest/