add exceptions docstrings & isort

src/fastapi_endpoints/exceptions.py

@@ -4,15 +4,25 @@
 
 
 class BaseOSException(Exception):
+    """The base exception used to manage the message in a dynamic way"""
+
     message: str
 
     def __init__(self):
         super().__init__(self.message)
 
 
 class InitializationError(BaseOSException):
+    """Error for any issue that comes when the routers are being fetched
+    and included in the app
+    """
+
     message = "Could not initialize routes as modules are not defined correctly"
 
 
 class RouterNotFound(BaseOSException):
+    """FastAPI APIRouter instance is not found in the router file
+    module.
+    """
+
     message = "Router module does not have an instance of APIRouter"

src/fastapi_endpoints/router.py

@@ -4,15 +4,13 @@
 
 import importlib
 import pkgutil
-
-from typing import Set
 from types import ModuleType
+from typing import Set
 
 import fastapi
 
 from . import exceptions, utils
 
-
 Excluded = Set[ModuleType]