Configure analytics dashboard to clearly and reliably report priority metrics

[hillaryl]

Sub-task: complete analytics training

Acceptance criteria:

• Key impact metrics identified (metrics that show reach and growth over time)
• Key signal metrics identified (metrics that provide insight into user behaviour useful for design)
• Reports are easy to locate and interpret in google analytics dashboard (maybe we need supporting documentation for this)
• We're confident that the data being collected is accurate
• Maybe: baseline metrics are reported somewhere in product documentation

Done when : product documentation is easily accessible highliting the metrics reported on in our GA reports and the (limited) insights or ccl we can draw from it.