Set up Google Tag Manager Events

Currently we have Google Analytics basic script running on the project. To get more detailed analytics we may wish to set up custom events using Google Tag Manager.

As a product owner
I want to be able to see how users are using my application
So that I can make changes based on these observations

We need to determine which events to track first.

@nelsonic @iteles @SimonLab - any things in particular that you'd like to track?