Spin 旋转提示

```html
      <h2 class="item-title">Spin-CSS</h2>
      <div class="spin-container">
        <spin size="40px" color="#ccc"/>
        <spin size="60px" color="#999"/>
        <spin size="80px" color="#666"/>
        <spin size="100px" color="#333"/>
      </div>

      <h2 class="item-title">SVG</h2>
      <div class="spin-container">
        <!-- 颜色要通过修改svg来实现，无法通过属性修改 -->
        <spin :svg-src="svgSrc" size="80px"/>
        <spin :svg-src="svgSrc" size="100px"/>
        <spin :svg-src="svgSrc" size="120px"/>
        <spin :svg-src="svgSrc" size="140px"/>
      </div>
      
   import svg from '@/assets/loading/rolling.svg'
 
   export default {
     data() {
       return {
           svgSrc: svg,
       }
     },         
                
```
