Provide developer remark for auto selection mode
Summary: Add remark on how to use the auto selection mode
Test Plan: manual proofreading
Reviewers: floca, O1 MITK Reviewer Group I
Reviewed By: floca, O1 MITK Reviewer Group I
Subscribers: kalali, floca
Maniphest Tasks: T27674
Differential Revision: https://phabricator.mitk.org/D398