docs: FAQ entry on logging + some minor clarification

[dgw]

Description

After I closed #2395 there was some question whether the FAQ added in #2533 actually covered everything that was requested.

Deciding that we could always do it better, @SnoopJ convinced me (it wasn't hard) to add more info about logs to the FAQ.

I also clarified a piece of the "Logging" section docs under "The [core] configuration section" because it confused me, too.

Checklist

• [x] I have read CONTRIBUTING.md
• [x] I can and do license this contribution under the EFLv2
• [x] No issues are reported by make qa (runs make lint and make test)
• [x] I have tested the functionality of the things this change touches

[dgw]

I should note that merging this should come with a follow-up PR (draft) updating the relevant issue template(s) to link to this entry from the "Relevant logs" field description. Assuming links are allowed there, that is. I haven't checked into that yet.