comark/sources/missing-list · Give ::sources a numbered list

::sources reads its sources from a numbered list, one link per item, and the citations point at the items by number. A block with no numbered list has nothing to cite, so every :cite in the document points at nothing.

Incorrect

::sources
- [Homing](https://en.wikipedia.org/wiki/Homing_pigeon)
::

lint-comark example.mdexample.md:1:1 comark/sources/missing-list::sources 1 needs a numbered list of links, such as 1. [Vite](https://vite.dev).Change the block as the message says.✖ 1 problem

Correct

::sources
1. [Homing](https://en.wikipedia.org/wiki/Homing_pigeon)
::

lint-comark example.md✔ No problems