This came up a number of years back, but was filed as a bug Bug with Numbered List. I’m fine with the classification of it not being a bug, but it would still be useful if lists could be started at arbitrary numbers/continued after writing something in between, e.g.
Top Prio:
1. Item 1
2. Item 2
3. Item 3
Medium Prio:
4. Item 4
5. Item 5
Low Prio:
6. Item 6
Edit:
The original request was to allow numbered lists that start with a number different from 1. But it turns out, this works (see below). However, it only works with an empty line before the numbering for numbers other than 1. So the suggestion would be to either handle other numbers similar to 1, i.e. render the list even if there is no empty line before it, or to adapt the behavior for lists starting with 1 to match that of the other numbers.