MxN Multi Widget F1-Help
Summary: Add F1-help page for the MxNMultiWidget / MxN Display
Test Plan: proofreading
Reviewers: floca, s434n, O1 MITK Reviewer Group I
Reviewed By: floca, O1 MITK Reviewer Group I
Subscribers: kislinsk, s434n, floca, kalali
Maniphest Tasks: T29491
Differential Revision: https://phabricator.mitk.org/D784