Count only merged and release PLIPs

[tisto]

There is no easy way to differentiate a merged and release PLIP and a PLIP that has been abandoned or rejected.

If I am not mistaken we currently do not have a label for a completed PLIP and we mark both the PLIP itself and the PR with "PLIP".

Almost all PLIPs have been closed with "reason:completed":

https://github.com/plone/Products.CMFPlone/issues?q=state%3Aclosed%20label%3A%2203%20type%3A%20feature%20(plip)%22%20reason%3Acompleted

Hard to believe that this is actually true.

@jensens you worked on the status labels in the past, right?

@sneridagh @mauritsvanrees we need some way to differentiate accepted and merged PLIPs from rejected ones. Options or suggestions how we could handle this?