insights: Show year on x-axis labels
Created by: Joelkw
We should either show year:
- When multiple years are shown on the graph
- All the time
1 is very much preferred but if it's more complicated than it's worth right now, 2 is okay.
This solves a problem of confusing-at-a-glance graphs (these are Sourcegraph or test insights, not customer insights, so okay to post here publicly):
