docs: 更新README.md中的iframe属性格式

将iframe的style属性替换为height和width属性，提高代码可读性

Author: ly525

README.md

@@ -34,7 +34,7 @@ $ brew install android-platform-tools
 
 使用scrcpy录制手机屏幕
 
-<iframe src="https://player.bilibili.com/player.html?isOutside=true&aid=114522887034628&bvid=BV1qzJwzAEPL&cid=30007626158&p=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true" style="height: 600px; width: 100%;"></iframe>
+<iframe src="https://player.bilibili.com/player.html?isOutside=true&aid=114522887034628&bvid=BV1qzJwzAEPL&cid=30007626158&p=1" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true" height="600" width="100%"></iframe>
 
 <details>
 <summary>点击展开详细说明</summary>