Add discard button to Create Content step 2

The user can add values to the fields of the new document. The X button on top gives the option to not create the document after all. An extra feature would be to add a Discard button at the bottom of the panel that clears all fields again. Note that fields with default values should show these.

Technically this boils down to deleting the newly created document, create a new clean document and load the step 2-editor again.