Markdown checklist formatter
Problem to solve
I miss Trello checklists.
Further details
We have all sorts of issues around putting issue lists in descriptions (and comments) (1, 2, 3, 4). We could build a first-class checklist concept into issues, but maybe we could do it as a markdown renderer instead. This gives maximum flexibility. I can have multiple checklists if I want, add whatever header I want, as well as introduce custom markdown without affecting general markdown.
Proposal
```checklist
* [ ] #1235
* [ ] foo#4312
```Would show the issues with the checklist state automatically determined by the state of the issue, with a header showing how many entries are complete out of the total. Maybe we could handle different formatting differently. Like if I don't include the [ ], then don't include the status. Maybe allow formatting options after the issue number, like
What does success look like, and how can we measure that?
(If no way to measure success, link to an issue that will implement a way to measure this)