Insert file name as default heading for new markdown files

[ChristophWurst]

Is your feature request related to a problem? Please describe.

As a Nextcloud user I often have to repeat the document title in the file name and the heading inside the document.

Describe the solution you'd like

When I create a file "Project plan.md", make the contents

# Project plan

Describe alternatives you've considered

N/a

Additional context

(MS) Office applications do this similarly where they take the document title as suggestion for the file name once you click Save.

This might need an opt-in.