comark/details/missing-summary · Give every ::details a summary

A ::details shows its summary while it's closed, so readers decide from it whether to open it. Without summary or a #summary slot, it shows "Details", which says nothing about what's inside.

Incorrect

::details
The ducks leave the pond at dusk.
::

lint-comark example.mdexample.md:1:1 comark/details/missing-summary::details 1 has no summary, so it shows "Details".Write ::details{summary="..."}, or a #summary slot.✖ 1 problem

Correct

::details{summary="When do the ducks leave?"}
The ducks leave the pond at dusk.
::

lint-comark example.md✔ No problems