Add documentation for upcoming API change
Add documentation for upcoming API change

ember-cli/broccoli,osxi/broccoli,broccolijs/broccoli,gabesoft/broccoli,gabesoft/broccoli,osxi/broccoli,broccolijs/broccoli,ember-cli/broccoli,gabesoft/broccoli,osxi/broccoli,broccolijs/broccoli,ember-cli/broccoli,broccolijs/broccoli