docs: add Sphinx documentation build and deploy workflow

- Add Gitea Actions workflow to build and deploy docs on push to main
- Generate Sphinx reference documentation for all apps and modules
- Deploy versioned and latest docs via rsync over SSH

docs/source/reference/apps/library/library.rst

@@ -0,0 +1,34 @@
+library package
+===============
+
+.. automodule:: library
+   :members:
+   :show-inheritance:
+   :undoc-members:
+
+Subpackages
+-----------
+
+.. toctree::
+   :maxdepth: 4
+
+   library.api
+   library.management
+   library.services
+
+Submodules
+----------
+
+.. toctree::
+   :maxdepth: 4
+
+   library.admin
+   library.apps
+   library.content_types
+   library.forms
+   library.metrics
+   library.models
+   library.tasks
+   library.urls
+   library.utils
+   library.views