feature request: gin commit --lock

[JuliaSprenger]

To add a new file to a repository in a locked state currently 3 steps are required as files can only be locked after being committed

• gin commit <filename>
• gin lock <filename>
• gin commit <filename>

This is inconvenient and created unnecessary commits. From the git-annex perspective it is possible (and the default behaviour) that files are locked when added to the staging area. This way only a single commit would be required to commit a file in a locked state. Would it be possible to add a --lock flag to gin committhat automatically locks the committed files to simplify this procedure?