docs(minerr): add note about ngRoute in injector/modulerr

Author: btford

docs/content/error/injector/modulerr.ngdoc

@@ -5,3 +5,7 @@
 
 This error occurs when a module fails to load due to some exception. The error
 message above should provide additional context.
+
+In AngularJS `1.2.0` and later, `ngRoute` has been moved ot its own module.
+If you are getting this error after upgrading to `1.2.x`, be sure that you've
+installed {@link api/ngRoute `ngRoute`}.