fix(example): add missing todo

Author: sigmundch

modules/examples/pubspec.yaml

@@ -17,7 +17,7 @@ dependency_overrides:
 transformers:
 - angular2:
     # The build currently fails on material files because there is not yet
-    # support for transforming cross-package urls.
+    # support for transforming cross-package urls. (see issue #2982)
     $exclude: 'web/src/material/**'
     entry_points:
         - web/src/hello_world/index_common.dart