Add API documentation generation and use Markdown (#160)

* Add package API documentation generation

Add generation of the API documentation for akkudoktoreos
and akkudoktoreosserver packages.

The API documentation is generated by the Sphinx autosummary extension.

Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>

* Enable Google style source commenting and documentation generation.

Enable automatic documentation generation from Google style docstrings in the source.

Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>

* Check Google style source commenting.

Check Google style commenting by the appropriate ruff rules.

Commenting is _NOT_ enforced. Missing docstrings are ignored.

Minor commenting quirks of the code base are adapted.

Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>

* Improve Markdown handling and switch to Markdown documentation.

Switch to Markdown for the documentation files to improve the user and developer experience (see issue #181).

Keep files with special directives for automatic API documentation in RST format. The
directives expect RST.

Also add dummy handling for openai/ swagger server documentation. The openai interface definition is
for now taken from the fastapi PR as EOS will switch to fastAPI.

Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>

---------

Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>
Co-authored-by: Normann <github@koldrack.com>

docs/index.md

@@ -0,0 +1,25 @@
+% SPDX-License-Identifier: Apache-2.0
+
+```{image} _static/logo.png
+
+```
+
+# Akkudoktor EOS documentation
+
+```{toctree}
+:maxdepth: 2
+:caption: 'Contents:'
+
+welcome.md
+akkudoktoreos/about.md
+develop/getting_started.md
+develop/CONTRIBUTING.md
+akkudoktoreosserver/serverapi.rst
+akkudoktoreos/api.rst
+```
+
+# Indices and tables
+
+- {ref}`genindex`
+- {ref}`modindex`
+- {ref}`search`