Recommendations for documentation platform which facilitates user comments / annotations?

Hi Everyone,

We are seeking a platform for documenting a rather complex software product. Key aspects:

• Can be self-hosted or hosted by a service provider.
• Free and commercial options are okay.
• We want to allow readers to contribute with comments, suggesting changes, etc. Ideally, there is a lightweight system for moderation.
• The readers don't have a background in IT or software development, so the solution must not rely on git knowledge, etc. We need a low barrier to entry for people who want to comment and annotate. The solution must not rely on e.g. having a GitHub account.
• The documentation will be rather exhaustive, more in a book style as in just a reference. (Think "The Missing Manual").
• The documentation is primarily text based, though the ability to integrate graphics and videos would be beneficial. Those could be hosted externally.

Looking forward to your suggestions.