Shift Enter in lists is undocumented

[colintedford]

Thank you for your time in completing this issue! 🙌

What is your suggestion?

Document what is meant to happen when one types Shift Enter in a list (and possibly also in a blockquote or anything else that can be auto-continued when pressing Enter).

What is the use case?

Learning that the feature exists and/or how to use it.

Have any context we can refer to?

This came up in the context of a question about some surprising behavior. https://discord.com/channels/686053708261228577/694233507500916796/1297327830669201452

It was eventually determined that Shift Enter, in addition to discontinuing the list, adds indentation, and adds a different amount depending on the length of a numbered list marker. https://discord.com/channels/686053708261228577/694233507500916796/1297340343901093920

It's unclear if the indentation or its varying length are intended, because the feature isn't documented. I've seen it mentioned in conversation before and always forget it exists, but it's not in the documentation of lists, and none of the matches when searching "shift+enter" are about it.

The feature might also apply to discontinuing blockquotes and/or other constructs.