The Hydrus docs are built with [MkDocs](https://www.mkdocs.org/) using the [Material for MkDocs](https://squidfunk.github.io/mkdocs-material/) theme. The .md files in the `docs` directory are converted into nice html in the `help` directory. This is done automatically in the built releases, but if you run from source, you will want to build your own.
Again in the base hydrus directory. It will host the help site at [http://127.0.0.1:8000/](http://127.0.0.1:8000/), and when you change a file, it will automatically rebuild and reload the page in your browser.