Warn that changing area won't change capacity in Tank

Co-authored-by: barneydobson <barnaby.dobson1@gmail.com>

wsimod/nodes/nodes.py

@@ -805,6 +805,8 @@ def apply_overrides(self, overrides: Dict[str, Any] = {}):
         """
         self.capacity = overrides.pop("capacity", 
                                       self.capacity)
+        if "area" in overrides.keys():
+            print("warning: when overriding area, capacity is not automatically recalculated")
         self.area = overrides.pop("area", 
                                   self.area)
         self.datum = overrides.pop("datum",