Update Readme.md

Fix usage of build badge for appveyor

Readme.md

@@ -10,8 +10,7 @@ Additionally, assimp features various __mesh post processing tools__: normals an
 This is the development trunk containing the latest features and bugfixes. For productive use though, we recommend one of the stable releases available from [assimp.sf.net](http://assimp.sf.net) or from *nix package repositories. According to [Travis-CI] (https://travis-ci.org/), the current build status is:
 
 [![Linux Build Status](https://travis-ci.org/assimp/assimp.png)](https://travis-ci.org/assimp/assimp)
-[![Windows Build Status](https://ci.appveyor.com/api/projects/status/tmo433wax6u6cjp4?svg=true)]
-
+[![Windows Build Status](https://ci.appveyor.com/api/projects/status/tmo433wax6u6cjp4?svg=true)](https://ci.appveyor.com/project/kimkulling/assimp)
 Coverity scan status report: <a href="https://scan.coverity.com/projects/5607">
   <img alt="Coverity Scan Build Status"
        src="https://scan.coverity.com/projects/5607/badge.svg"/>