added nuget tags

Author: MehdiK

NuGet/TestStack.BDDfy/TestStack.BDDfy.nuspec

@@ -10,5 +10,6 @@
     <description>BDDfy is the simplest BDD framework to use and extend</description>
 	  <projectUrl>https://github.com/TestStack/TestStack.BDDfy</projectUrl>
     <licenseUrl>https://github.com/TestStack/TestStack.BDDfy/blob/master/license.txt</licenseUrl>
+    <tags>BDD testing</tags>
   </metadata>
 </package>