Add error message for scheduling algorithms that haven't been implemented yet.

b_asic/schema.py

@@ -31,7 +31,7 @@ class Schema:
         if scheduling_alg == "ASAP":
             self._schedule_asap()
         else:
-            raise NotImplementedError
+            raise NotImplementedError(f"No algorithm with name: {scheduling_alg} defined.")
 
         max_end_time = 0
         for op_id, op_start_time in self._start_times.items():