List Editing Design

Design notes for #674 and future list editing work.

- [ ] Add more examples for how operations work to solve list editing actions
- [ ] Add collab examples
I think readability would be improved here to list the scenarios TOC style before breaking into each in detail. In MarkDown, you can do anchors + internal links.... it really depends on the longevity & expected use of this document however, so I have no strong opinion on it :smiley: