Changing custom Page Headers in Admin GUI

Hey guys!
Loving Grav so far. Quick question:
Is there a way to change a custom page header option in the GUI of the Administration Panel?
Basically I have a page that has the next header
--- md

next:
l_link: 'a'
l_img: './user/themes/get/images/next_items/tv/gameup.png'
r_link: 'b'
r_img: './user/themes/get/images/next_items/mac/urban.png''

Two options that determine which images to show on the page. The logic is that the page shows upcoming events/stuff from my company so those options can change anytime. I wan to be able to change it in some kind of field in the Admin GUI page editor (maybe in Settings tab? But it doesn't show there), but I can't seem to find an easy way. **I can just toggle Expert mode and change in the frontmatter, but is not good for people that do not know coding. Is there a way to put my custome headers in the Settings tab in the Page editor?**.

Thanks in advance!

You can add custom fields for any page. Check out the blueprints documentation.

Not really. The fields specified in blueprints.yaml are more theme-based and I can access it in template, but not precisely owned by a page. Plus they are modified in the theme option of the Admin
Anyway, this works great, thanks!

Still, *there is NO way to add a custom field in the Admin GUI page editor?**

Forget it. You answered my question in gitter haha thanks.
For anyone interested: You can add an item to the Admin GUI by defining a blueprint just like you do with a Plugin by creating a blueprints folder in your theme and then following you page structure.

Example: blueprints->modular->features.yaml. They are based on system->blueprints->pages->default.yaml