This documentation is automatically generated from the main branch of the Swift-DocC repository. As mentioned in the Swift-DocC is Now Open Source blog post, there is a longer-term goal to start hosting documentation for more packages of the Swift project.
Fantastic! I guess the different style sheet between Apple and Swift hosted docs is intentional, is that correct? In the same vein, I suppose that custom docc-renderers shouldn't be allowed to mimic Apple's css?
Looks great! The only thing I'm worried about is whether documentation hosted on swift.org will appear high enough in search results, since I doubt that it (yet) has as much traffic as other websites. I hope that once other packages such as the Standard Library are (hopefully) moved to swift.org, the links to the documentation hosted on developer.apple.com won't be fully removed, and will just redirect to the documentation hosted on swift.org.
Yes, the idea is to create a unique experience for the open source project. Over time many folks in the community have a desire to build theme support to make it even easier to create totally unique customizations for their docs. The possibilities are pretty exciting.