Update information regarding wizards provided by the
AutoTest plugin.
Add a note for the missing wizard for adding Qt test
based test cases.
Task-number: QTCREATORBUG-30139
Change-Id: I33a3e176e8debcdff05d0183f3ad890996316584
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>