Visually indicate that an item has been linked

Imagine I link from item B to item A:

- item A
- item B [item A](link)

When looking at item A, I want to see a visual indication that the item has been linked. That way, I don’t accidentally delete item A and break the link, and I can follow the association from item A back to item B if necessary by searching for the link URL.

Workflowy does this by adding a blue dot around the linked item: