Feature Request: New notebook from cell(s)

[triptych]

Is your feature request related to a problem? Please describe. After working on a notebook, often I would like to refactor / extract a particular cell or set of cells. I would like to click a cell and choose "new notebook with this cell" or perhaps some way similar to Embed where you can choose cells to embed - instead choose cells to copy to a new notebook.

Describe the solution you'd like Just like the Embed functionality where you can choose multiple cells, allow someone to choose 1 or more cells to spin off into a new notebook.

Users might even create a base notebook with helper utilities that they use to spawn notebooks.

Describe alternatives you've considered Reuse embed cells and manually create a new notebook. Fork the notebook and delete the cells I don't want to use.

Additional context

[mootari]

This might be a duplicate of https://github.com/observablehq/feedback/issues/255

[triptych]

Yes, very close