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/core/database/conftest.py

@@ -8,6 +8,8 @@ from unittest.mock import MagicMock
 def connection() -> Connection:
     """
     mock object for sqlite3 connection
-    :return: sqlite3 connection test instance
+
+    Returns:
+        Connection: sqlite3 connection test instance
     """
     return MagicMock()

tests/ahriman/core/database/migrations/conftest.py

@@ -9,7 +9,11 @@ from ahriman.core.database.migrations import Migrations
 def migrations(connection: Connection) -> Migrations:
     """
     fixture for migrations object
-    :param connection: sqlite connection fixture
-    :return: migrations test instance
+
+    Args:
+        connection(Connection): sqlite connection fixture
+
+    Returns:
+        Migrations: migrations test instance
     """
     return Migrations(connection)