Add global variables at the "Project" level (that can be used in Liquid)

Allow some key:value pairs to be stored at the Project level, available to all templates within. My initial use-case is having Fusion url (including credentials) in one place, but usable throughout a Project {% fetch_json user ={{globals.user_endpoint_url}}?id={{user.user_id}} %} would make managing that kind of thing a little safer and a lot easier.