Add docs for setting up ansible-test

[TheFriendlyCoder]

Summary

The current docs that describe how to use ansible-test for unit testing collections, assumes that the user will/can use Docker for delegating the test behaviour to. This can not always be done (ie: in the case of a limited build environment without direct access to a Docker daemon). Further, it is not clear from the docs how to set up your build environment to work WITHOUT Docker. For example, when I ran ansible-test for the first time on a simple hello-world collection I created, I first got errors complaining about pytest package being missing. Then, after installing that package, I ended up with a cryptic error which looked like this:

ERROR: usage: __main__.py [options] [file_or_dir] [file_or_dir] [...]
__main__.py: error: unrecognized arguments: -n tests/unit/plugins/action/test_thing.py
  inifile: /Users/myname/src/ansible/ansible_collections/local/fubar/venv/lib/python3.12/site-packages/ansible_test/_data/pytest/config/default.ini
  rootdir: /Users/myname/src/ansible/ansible_collections/local/fubar

FATAL: Command "pytest -r a -n auto --color yes -p no:cacheprovider -c /Users/myname/src/ansible/ansible_collections/local/fubar/venv/lib/python3.12/site-packages/ansible_test/_data/pytest/config/default.ini --junit-xml /Users/myname/src/ansible/ansible_collections/local/fubar/tests/output/junit/python3.12-controller-units.xml --strict-markers --rootdir /Users/myname/src/ansible/ansible_collections/local/fubar --confcutdir /Users/myname/src/ansible/ansible_collections/local/fubar -vvv tests/unit/plugins/action/test_thing.py" returned exit status 4.

this error didn't provide sufficient information for me to deduce how to proceed next. After I did some considerable digging was able to discover that I needed several additional Python packages installed (ie: pytest-xdist and pytest-mock) to get the simple test suite working. It would have saved me considerable time and effort if this information was just provided in the docs somewhere.

Issue Type

Documentation Report

Component Name

ansible-test

Ansible Version

ansible [core 2.16.5]

Configuration

na

OS / Environment

na

Additional Information

na

Code of Conduct

• I agree to follow the Ansible Code of Conduct

[ansibot]

Files identified in the description:

• bin/ansible-test

If these files are incorrect, please update the component name section of the description or use the component bot command.