Add small TODO in DataMisfit (#60)

Author: santisoler

src/inversion_ideas/data_misfit.py

@@ -85,6 +85,8 @@ def __init__(
         cache=False,
         build_hessian=False,
     ):
+        # TODO: Check that the data and uncertainties have the size as ndata in the
+        #       simulation.
         self.data = data
         self.uncertainty = uncertainty
         self.simulation = simulation