Looking at the landing page, I have built some hypothetical mental model on how to use the app and its feature, but it's mostly guessing - it would be awesome if they put up a video showcasing real-world usage and features.
"Task Board, Design Specs, Knowledge Base, Coding Docs, Team Handbook, Roadmap" - are these possible use-cases of the system? Or are they disparate document types? You create a document and pick one of these types which determines its features and layout?
"lets you nest pages inside each other" - does this mean hyperlinking?
"No more markup" - so WYSIWYG, just like Google Docs, Quip, MS Office, etc?
"Love using Trello" - I don't know what Trello is.
There's Slack notifications, but can you @tag people?