I would recommend Prismic.io. They have what I have searched for on anothers services: slices. This allows you to have different block and empower people to use them as they want to create landing pages for instance.
650 karma · joined September 21, 2011
I don't like the github merge button so I don't use it.
Also I always rebase on master, and squash/edit some commits before merging on master.
It allows you to focus on a problem or a challenge, for 10min to 1hour, and have a nice creative output of the workshop.
Btw, it's not the silver bullet to improve your creativity, you still need a great facilitator, but many brains are better than one :).