Allow faster editing

I'm currently updating a few desciptions on things, and while gallery has a number of useful keyboard shortcuts, I can't seem to use `ctrl+enter` or similar to hit submit. I'd like to be able to go through a folder and update description and members for a number of objects entirely using the keyboard. This is achievable using tab based navigation, which is a very workable option, but `ctrl+enter` has become a default reflex for me because of things like github

Possibly worth spinning off another issue for: is there anywhere other than the keyboard shortcuts help menu that mentions there are keyboard shortcuts?

Start at the gallery's editing form and the existing keyboard-shortcuts help menu, both referenced in the issue, and trace how description and member edits are submitted. Add a keyboard submission path for these edits and verify that updating several objects through keyboard navigation works as intended.

Written by the indexing model from the issue text.