[RFC] Maintainer Dashboard - Better way to calculate inactivity for maintainers who haven't been active

[bshien]

Is your feature request related to a problem?

Currently, the calculation performed whether someone is active or inactive is a linear equation described in this issue: #75

This is not the best way to calculate inactivity as due to the spread of repos' event counts, most repos would lie on the "waiting-longer" end of the graph while only a few of the most active repos would lie on the "waiting-shorter" end.

What solution would you like?

Using something other than a linear equation, potentially another type of equation or something rank-based.

Do you have any additional context?

Part of #75