Improve wording to emphasize static behavior about measuring maintenance

[manuyavuz]

Currently, Very Popular and Popular badges has the following descriptions:

• Very Popular : The popularity of a project is a useful way of discovering if it is useful, _and well maintained_.
• Popular : A popular library means there can be a community to help improve and _maintain_ a project.

However, we currently do not have such metrics to measure maintenance over time, and the wording does not imply the fact that all these measurements are done according to the state of the pod repo at the release time.

Also some badges like Lots of open issues could no more be valid when some time passed after the release, or the reverse.

I think we should improve wording a little, but as a foreign I do not have exact suggestions.

[neonichu]

Maybe we can amend the introductory statement:

All pods start with 50 points on the quality estimate, we then add or remove to the score based on the following rules

with something like

which are evaluated once when a Pod is published

[orta]

I'm happy to have these changes