For example:
1. item1
indented item, but not a list (1)
2. item2
3. item3
indented item, with a blank line before and after (2)
4. item4, continue the list
How to produce (1) and (2)?
You can add the additional rows using Shift+Enter, and then indent them using Shift+Tab
Here is an example Doc: https://docs.google.com/document/d/1tn-uFn87bsP4D67uaNhlKv2pxItDfEwbkHWw-vPphpo/edit?usp=sharing