Do not attempt to add the designer file as part of the tt generation

This results in multiple copies of the .Designer file being added to the
project in different locations which gets confusing.

build/Resources.tt

@@ -116,9 +116,6 @@ namespace {0}
 
     File.WriteAllText(outputPath, GenerationEnvironment.ToString());
     GenerationEnvironment.Length = 0;
-
-    var resxProjectItem = dte.Solution.FindProjectItem(resxFile);
-    resxProjectItem.ProjectItems.AddFromFile(outputPath);
 }
 #>
 <#+