Add SvgViewer image to README-zh.md

Added an image for SvgViewer section in README-zh.md.

Author: yanjinhuagood

README-zh.md

@@ -120,6 +120,7 @@ xmlns:wd="https://github.com/WPFDevelopersOrg/WPFDevelopers"
 <img src="https://gitee.com/WPFDevelopersOrg/MarkDownBlog/raw/master/resources/WPFDevelopersResource/BasicControls02.gif"/>    
 <img src="https://gitee.com/WPFDevelopersOrg/MarkDownBlog/raw/master/resources/WPFDevelopersResource/BasicControls03.gif"/>    
 <img src="https://gitee.com/WPFDevelopersOrg/MarkDownBlog/raw/master/resources/WPFDevelopersResource/BasicControls04.gif"/>    
+
 ----------
 ### SvgViewer