An active node can become a community by creating their own website. You can Fork the Tree3 Frontend code and modify it based on your liking or you can use T3 API to create your own community code with any features you want. Creating a community allows you to earn 50% revenue from the fees which is a very good amount and you can design/moderate/manage your website/community in any way you want.
Currently we are not allowing creation of community nodes since usage of private key is an issue and any wrong actor can steal users key by modifying the code. We are working on a better way for key storage which will allow users to use T3 Desktop application to submit content to any community and hence removal of usage of keys from frontend.
Tree3 Platform Alpha version is an example of a community that can be created using Tree3 Platform.
This docs needs update based on T3 desktop application