docs: user module

In-line and Swagger docs improvements on the User module and endpoints

src/user/exceptions.py

@@ -4,4 +4,16 @@ Module specific exceptions for user module
 Exceptions:
  - List: Description
  - Exceptions: Description
-"""
+"""
+from typing import Optional
+
+from fastapi import HTTPException, status
+
+
+class UserNotFoundException(HTTPException):
+	def __init__(self, user_id: Optional[int] = None) -> None:
+		detail = "User not found" if user_id is None else f"User with ID '{user_id}' was not found."
+		super().__init__(
+			status_code=status.HTTP_404_NOT_FOUND,
+			detail=detail,
+		)