Ask HN: How would you do an Internal Knowledgebase with these reqs?

I wanted to ask the HN community what they would use for an internal knowledgebase (henceforth IKB). The most important feature is the notifications, so people see when key documents change. Answers could range from buying SaaS, to configuring something like dokku-wiki, to rolling your own maybe starting with a nub of software from github. It might be cool if app was just like Quip, but with a Table of Contents view and team/user notifications layered on. Or maybe like a Github wiki, but with notifications. Audience The audience for the IKB includes developers, who might write or edit articles, as well as communications people, who would would read, write, and edit articles. Purpose The purpose of the IKB is to host articles that people at the company should know about. Examples might include information about the product to help do support, style guides for writing, company policies, and other operational documents. New employees might read all or sections of this, and perhaps more importantly, certain employees would get notifications when articles are added, closed, or updated. Requirements - Must Have * WYSIWYG text editor (creates markdown/HTML) * categories * search * notifications - about new, closed, and updated articles - targeted by team/group and user - teams can be notified about a category - individuals can subscribe to changes to an article Requirements - Nice to Have * version control - view edit history - rollback articles - close instead of delete articles - closed show up in search, but not in ToC - closed articles can be re-opened * autocompleting search * table of contents * openauth/similar to integrate with company logins that exist