Update docs/README.md

docs/README.md

@@ -13,8 +13,14 @@ 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 install` 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 install`.
+
 Once this is done, rerun `./configure` in the jq root directory and then
-the Makefile will be able to generate the jq manpage.
+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`.
 
 To build the website, run `pipenv run ./build_website.py` from inside
 the `docs` directory.