TextInputMenuSelectWidget: Correct documentation
TextInputMenuSelectWidget: Correct documentation

Remove confusing remarks about frames; while true, they're not very
relevant now that we removed isolation.

Change-Id: Ifec69d83aef39c7cae65b41074e389c82c7638f3
wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui