Avo 3.0 release notes

We brought up a few new things:

• panels can not receive show_on: :index. That will take all the fields inside that panel and display them on the index screen
• you have access to the main_panel. This will hold the resource name, description, buttons and more.
• panels can now hold tools.
• tools can be added inside body statements inside panel statements
• tools can come before fields using main_panel
• bodys can have the type of :clear to not wrap everything in a white container (aliased to clear_body)
• sidebars can have multiple panels by declaring multiple sidebar statements