Use type hints when getting config object (#773)

The `get_config` class method now uses type hints which helps IDEs (and
me)

Signed-off-by: Juan Antonio Osorio <[email protected]>

Author: JAORMX

src/codegate/config.py

@@ -360,5 +360,5 @@ def load(
         return config
 
     @classmethod
-    def get_config(cls):
+    def get_config(cls) -> "Config":
         return cls.__config