I'm missing this feature for years.
In many notes I'm keeping quotes from various sources:
Quotes from interviews, mixed with my thoughts
Quotes from conversation in messengers with my mates
For quotes I need a block, similar to "Code", that has two editable parts:
Header, that holds meta-information, like "John Smith in Skype 2020.12.18 wrote"
Body, that holds content with formatted text, images, tables, files etc.
I've created a design mockup with different variants of quote block and a new button "Quote" in "Insert" menu.
Take a look at the attached image.