First, install some dependencies needed to build the docs:

make install-deps

Then, you can build the docs by:

make build

In system with a desktop GUI (i.e. non-headless systems), you can open the built docs with the command:

make open

which makes use of the command open. If you're on Linux and open does not work you can add alias open='xdg-open to you rc-file.

To both build the html files and open them, do:

make see