Add Avo Resource generator

We want to generate an Avo resource generator for admin that has nice sidebar layout

https://docs.avohq.io/3.0/resource-sidebar.html

Should auto detect post types nicely and handle future features like taxonomies, etc


Possibly register as https://avohq.io/blueprints type of approach

See complex examples in https://github.com/avo-hq/main.avodemo.com like Project and User