Include org-modern-indent as an extension?

Hi @minad. I recently overhauled `org-modern-indent` to be much more robust. It's now using `org-element`. I'm considering submitting to ELPA, but thought I'd check with you first. If you'd be interested in incorporating it as an extension to `org-modern`, I'd be happy to support that, to keep package clutter down. That said, its operation is more complex than the primarily keyword font-locking `org-modern` performs (though still <400LOC) . It uses before/after change functions (like `org-indent`), together with `org-element` for robust block identification and change detection. I'd fully understand if you'd prefer not to onboard that complexity, but thought I'd check in first. Happy either way.