Document360 is described as 'AI-powered platform for creating knowledge bases and documentation, with customizable themes, real-time team collaboration, version control, and multi-language support for internal and external use' and is a Help Desk platform in the business & commerce category. There are more than 50 alternatives to Document360, not only websites but also apps for a variety of platforms, including SaaS, iPhone, Android and Windows apps. The best Document360 alternative is ProProfs Knowledge Base. It's not free, so if you're looking for a free alternative, you could try Slite or Sonat. Other great sites and apps similar to Document360 are Confluence, Zendesk, DocsHound and Notaku.
Lots of markdown extensions supported. Very convenient editor toolbar. Liv preview. Simple to use, fast, cheap. Also features a free version.