If you are looking for Badger documentation, you might find https://dgraph.io/docs/badger much more readable.
We use Hugo for our documentation.
Download and install the latest patch of hugo version v0.69.x from here.
From within the docs folder, run the command below to get the theme.
cd themes && git clone https://github.com/dgraph-io/hugo-docs
Run hugo server within the docs folder and visit http://localhost:1313 to see the documentation site.