feat(ui/migrations): add placeholder to clarify empty description behavior (#7373)
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7373
Reviewed-by: 0ko <0ko@noreply.codeberg.org>
Co-authored-by: Mat <m.falkowski@dotmat.de>
Co-committed-by: Mat <m.falkowski@dotmat.de>