Enter at the end of a `> ` line now starts the next line with `> `, mirroring list continuation. Nested `> > ` keeps its depth, and Enter on an empty quote drops the marker to exit. Generalises `list_marker` to `continuation_marker`.
Enter at the end of a `> ` line now starts the next line with `> `, mirroring list continuation. Nested `> > ` keeps its depth, and Enter on an empty quote drops the marker to exit. Generalises `list_marker` to `continuation_marker`.