Add future todos on kan_block

Author: ndem0

pina/_src/model/block/kan_block.py

@@ -6,7 +6,11 @@
 from pina._src.model.spline import Spline
 from pina._src.model.vectorized_spline import VectorizedSpline
 
-
+# TODO
+# - Improve documentation and comments throughout the code for better clarity.
+# - Remove any unused parameters or code related to the base function if it's
+#       not being utilized in the current implementation.
+# - Clean unused code
 class KANBlock(torch.nn.Module):
     """define a KAN layer using splines"""