[CoLab] Add 'field placeholder' to ThreadedDiscussion
Considered that it may not be clear that Authors can identify that they can capture feedback in the ThreadeDisucssion reply field on the /submit
page. The ThreadedDiscussion does not utilise the 'Field placeholder this could be used to identify/provide further instruction to the author.
The suggestion is to add the 'Field placeholder' field to the Forms>Decision>ThreadedDiscussion
settings