doc: updated IMM filter documentation

src/filters.py

@@ -77,6 +77,9 @@ class IMM:
     def __init__(self, filters, sensor_model, transition_prob):
         """An implementation of an Interacting Multiple Model filter.
 
+        NOTE: Not a good implementation in the sense that it needs a specialized
+        tracker implementation to actually be useable, see src.trackers.IMMTracker.
+
         Parameters
         ----------
         filters : list