Document clean up changes to usage_ping.rb
Type of issue
Problem to solve
We have little to no documentation on usage ping or how it's meant to be used.
What audience is it intended for? (What roles and scenarios?)
As a starting point, once this issue is merged, we should document steps on how to implement usage ping into the GitLab codebase.
Who can address the issue
It would be great to have folks who have worked with usage ping in the past or who helped build it to have input.