Docs how to test (2nd) (#24094)

* Big testing doc refactor
* Combine all the testing documentation in to one place to make it easier to find
* Convert everything to RST
* Create testing_network guide
* Create testing landing page
* For each section detail "how to run" and "how to extend testing"
* More examples
* Lots more detail

docs/docsite/rst/dev_guide/testing_sanity.rst

@@ -0,0 +1,75 @@
+************
+Sanity Tests
+************
+
+.. contents:: Topics
+
+Sanity tests are made up of scripts and tools used to perform static code analysis.
+The primary purpose of these tests is to enforce Ansible coding standards and requirements.
+
+Tests are run with ``ansible-test sanity``.
+All available tests are run unless the ``--test`` option is used.
+
+Available Tests
+===============
+
+Tests can be listed with ``ansible-test sanity --list-tests``.
+
+This list is a combination of two different categories of tests, "Code Smell" and "Built-in".
+
+Code Smell Tests
+----------------
+
+Miscellaneous `scripts <https://github.com/ansible/ansible/tree/devel/test/sanity/code-smell/>`_ used for enforcing coding standards and requirements, identifying trip hazards, etc.
+
+These tests are listed and accessed by script name. There is no actual test named ``code-smell``.
+
+All executable scripts added to the ``code-smell`` directory are automatically detected and executed by ``ansible-test``.
+
+Scripts in the directory which fail can be skipped by adding them to `skip.txt <https://github.com/ansible/ansible/blob/devel/test/sanity/code-smell/skip.txt>`_.
+This is useful for scripts which identify issues that have not yet been resolved in the code base.
+
+Files tested are specific to the individual test scripts and are not affected by command line arguments.
+
+Built-in Tests
+--------------
+
+These tests are integrated directly into ``ansible-test``.
+All files relevant to each test are tested unless specific files are specified.
+
+A full list of tests can be obtained by doing ``ansible-test sanity --list-tests``.
+
+ansible-doc
+~~~~~~~~~~~
+
+Verifies that ``ansible-doc`` can parse module documentation on all supported python versions.
+
+pep8
+~~~~
+
+Python static analysis for PEP 8 style guideline compliance. See :doc:`testing_pep8` for more information.
+
+pylint
+~~~~~~
+
+Python static analysis for common programming errors.
+
+rstcheck
+~~~~~~~~
+
+Check reStructuredText files for syntax and formatting issues.
+
+shellcheck
+~~~~~~~~~~
+
+Static code analysis for shell scripts using the excellent `shellcheck <https://www.shellcheck.net/>`_ tool.
+
+validate-modules
+~~~~~~~~~~~~~~~~
+
+Analyze modules for common issues in code and documentation. See :doc:`testing_validate-modules` for more information.
+
+yamllint
+~~~~~~~~
+
+Check YAML files for syntax and formatting issues.