feat: add autoapi docs usage (#363)

Co-authored-by: Jorge Martínez <[email protected]>

doc/source/user_guide/autoapi.rst

@@ -0,0 +1,73 @@
+.. _ref_user_guide_autoapi:
+
+Using ``sphinx-autoapi`` to generate API documentation
+------------------------------------------------------
+
+`sphinx-autoapi <https://github.com/readthedocs/sphinx-autoapi/>`_ is a tool that automatically generates API documentation from your source code.
+It is a great way to keep your documentation up-to-date with your codebase.
+
+The ``ansys-sphinx-theme`` includes a set of custom templates for ``sphinx-autoapi`` that is designed
+to match the look and feel of the rest of the PyAnsys documentation.
+
+Dependencies required
+~~~~~~~~~~~~~~~~~~~~~
+
+To use ``sphinx-autoapi`` with the ``ansys-sphinx-theme``, you need to install the ``autoapi`` target
+of the theme. This can be done by defining your ``ansys-sphinx-theme`` dependency as
+``ansys-sphinx-theme[autoapi]`` in your project's requirements location.
+
+For example, if you are using a ``requirements.txt`` file, you would define your dependency as follows:
+
+.. code-block: text
+
+    ansys-sphinx-theme[autoapi]==X.Y.Z
+
+If you are using a ``pyproject.toml`` file, you would define your dependency as follows:
+
+.. code:: toml
+    
+    # For a typical PyAnsys pyproject.toml file
+    [project.optional-dependencies]
+    doc = [
+        "ansys-sphinx-theme[autoapi]==X.Y.Z",
+    ]
+
+Configuring our Sphinx project
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+To use ``sphinx-autoapi`` with the ``ansys-sphinx-theme``, and benefit from the shipped
+templates, you need to add the following configuration to your Sphinx project's ``conf.py`` file.
+
+.. code:: python
+
+    from pathlib import Path
+
+    from ansys_sphinx_theme import get_autoapi_templates_dir_relative_path
+
+    ...
+
+    # Configuration for Sphinx autoapi
+    autoapi_type = "python"
+    autoapi_dirs = ["../../src/ansys"]
+    autoapi_root = "api"
+    autoapi_options = [
+        "members",
+        "undoc-members",
+        "show-inheritance",
+        "show-module-summary",
+        "special-members",
+    ]
+    autoapi_template_dir = get_autoapi_templates_dir_relative_path(Path(__file__))
+    autoapi_python_use_implicit_namespaces = True
+    autoapi_keep_files = True
+    autoapi_own_page_level = "class"
+
+
+The above configuration generates the API documentation for your package in the ``src`` directory
+and places the generated files in the ``api`` directory. These files are based on the
+``ansys-sphinx-theme`` templates. If you want to customize some of the previous options, you can
+do so by modifying the configuration above. The line of code declaring the desired set of templates is the following one:
+
+.. code:: python
+
+    autoapi_template_dir = get_autoapi_templates_dir_relative_path(Path(__file__))

doc/source/user_guide/index.rst

@@ -18,4 +18,5 @@ While the Ansys Sphinx theme is often used as is, you can customize the followin
    pdf
    404_page
    extensions
+   autoapi