Permalink does not support multi-line highlight

The following discussion from !181901 (merged) should be addressed:

• @markrian started a discussion:

  suggestion (non-blocking): Ooh, I think this is the source of a bug that's been bothering me 😄

  If you have a multi-line highlight, e.g., #L5-10, pressing y drops the multi-line part of the hash, i.e., becomes just #L5.

  Worth opening a follow-up for?