pass-through on `revision_analysis` docs

[dsweber2]

Apparently they're somewhat confusing, so I should do a minor rewrite.

• min_lag is about first entry not time to first revision

[brookslogan]

(I also felt time_near_latest was confusing and have an adjustment in #540. That depends on some other change and I'm still working on documentation + splitting out the 2 things being handled by that PR. I could tackle this in #540 or just rebase it on top of changes for this issue.)

[dsweber2]

It could probably use edits from someone who isn't me as well. Feel free to ping me with questions if you decide to edit the docs.

[dsweber2]

Probably should've closed this back in January when we did it. Thanks @brookslogan