Documentation clarification on markdown list markers

[joshrotenberg]

The markdown list markers in a list in the SUMMARY.md must be of the same type to avoid creating a new list, which results in the remaining list items not being rendered. This should arguably produce an error or be handled in some other way, but in lieu of that, here is some documentation.

This clarifies the issue seen in #1517.

[ehuss]

Thanks for the PR! I'm wondering, since this is an issue that should be extremely rare, could the clarification perhaps be a little shorter? It takes up a significant amount of space, and I'd like to retain as much clarity here. Perhaps something like this?

Numbered chapters can be denoted with either - or * (do not mix delimiters).

[joshrotenberg]

You're right. I shortened it.

[ehuss]

Thanks!