Docstring update (#58)

* migrate docstrings from reST to google format

* add raises note

Also change behaviour of the `from_option` method to fallback to
disabled instead of raising exception on unknown option

* fix part of warnings for sphinx

* make identation a bit more readable

* review fixes

* add verbose description for properties to make them parsed by sphinx extenstion

* add demo sphinx generator

tests/ahriman/models/test_package_source.py

@@ -9,9 +9,13 @@ from ahriman.models.package_source import PackageSource
 def _is_file_mock(is_any_file: bool, is_pkgbuild: bool) -> Callable[[Path], bool]:
     """
     helper to mock is_file method
-    :param is_any_file: value which will be return for any file
-    :param is_pkgbuild: value which will be return if PKGBUILD like path asked
-    :return: side effect function for the mocker object
+
+    Args:
+        is_any_file(bool): value which will be return for any file
+        is_pkgbuild(bool): value which will be return if PKGBUILD like path asked
+
+    Returns:
+        Callable[[Path], bool]: side effect function for the mocker object
     """
     side_effect: Callable[[Path], bool] = lambda source: is_pkgbuild if source.name == "PKGBUILD" else is_any_file
     return side_effect