Don't we need the separate community for Ionic? Ionic is the biggest Hybrid app development framework. It should have its separate community to discuss the problems in the app development in Ionic Framework.
I'm going to close this as a duplicate of how to actually propose a site, but for anyone looking to post similar questions…
The entire purpose of Area 51 is to test this question: "Does a subject have sufficient content and support to launch a successful site?" As discussed in Changes to the Area 51 process, it is generally assumed you have access to a community to actually build your site. The [Ionic community] is not hanging out here, and Area 51 cannot find that community for you.
And as a final note about the specific subject you are asking about — Ionic is an example of an app platform for web developers which is heavily supported on Stack Overflow. As such, we do not generally split off a new site simply to give a subject its own space. I hope you will direct your community to Stack Overflow. The proposal would almost certainly be closed as a subject already covered by a live site.