Custom Editor Button

In the main editor is there a simple way to add a button?
I would like to to add a <pre></pre> button to make using the prism highlighting easier.

It seems such a simple thing but I cannot find a plugin or even guide to achieve this.

Thanks for any suggestions.

I believe Youtube plugin adds a button. Check this script

Thank you, I have had a look and it would add a button but it prompts for entry instead of using the text selected.
I do not know enough to convert it.

But it has what you need if you're looking for code wrapping or just adding a markdown tags. All is in the if (videoURL) {} condition. Just requires some adaptation and changes.

Anyway, it's good you found a solution that satisfies you

In case anyone stumbles across this thread and like me wants to add buttons:
I searched Grav's files and found the button configuration here:

/user/plugins/admin/themes/grav/js/admin.min.js
and
/user/plugins/admin/themes/grav/app/forms/fields/editor/buttons.js