Canvas: customizable header system for cards, groups, files

Use case or problem

Weak customization: now all cards and pictures do not have headers, and all group - forced to have.

Proposed solution

Add to menu new button - “header”, which create header window as it is now when creating a new group but for any card, group, picture or another file.
It would be nice to be able to choose location - top or bottom, and font size. This is how you can implement headers and comments to files in a single system.