The jq website, manpages and some of the tests are generated from this directory. The manual is a YAML file in content/manual.
To build the documentation (including building the jq manpage), you'll need python3 and pipenv. You can install pipenv like so:
pip install pipenv
Though, you may need to say pip3 instead, depending on your system. Once you have pipenv installed, you can install the dependencies by running pipenv sync from the docs directory.
Also, you may need to run virtualenv -p /usr/bin/python3 venv/ and then source venv/bin/activate, and only then pipenv sync.
Once this is done, rerun ./configure in the jq root directory and then the Makefile will be able to generate the jq manpage. You can also just run pipenv run build_manpage.py in the docs directory to build the jq.1 page manually, and pipenv run build_mantests.py to build the contents of tests/man.test and tests/manonig.test.
To build the website, run pipenv run ./build_website.py from inside the docs directory.