1，完善readme

Author: FlyJingFish

README.md

@@ -270,7 +270,7 @@ text7.setHtmlText("哈哈哈<a>lala</a>啦啦<a href=\"haha\">haha</a>哈哈哈<
 
 ## HtmlImage parameter list
 |property|parameter type|description|
-|---|:---:|:-------------------------------------- ----------:|
+|---|:---:|:------------------------------------------------:|
 |imagePlaceHolder|@DrawableRes int| Id of the image resource when the network image is loaded |
 |maxWidth|float| The maximum width of the picture (unit: DP) |
 |maxHeight|float| Maximum image height (unit: DP) |