Seeking Developer for 'Add Subtab' Feature in Frappe

Hello frappe community. I need to create an app that will add an ‘Add Subtab’ button in the Edit Doctype window, in every doctype. By subtab, I mean a tab nested within a regular tab. I’m open to offering a reward to someone who can make this kind of app.

Hello frappe community. I need to create an app that will add an ‘Add Subtab’ button in the Edit Doctype window, in every doctype. By subtab, I mean a tab nested within a regular tab. I’m open to offering a reward to someone who can make this kind of app.

Sub-tab for what? I don’t think we can use an “App” to extend the core doctype but we can either fork Frappe or override the core file in a CI/CD process.