add docs to split_shuffle_tutorial.ipynb

src/user_keypad.py

@@ -61,7 +61,7 @@ class UserKeypad:
         # shuffle all keys
         keypad_mat = self.keypad_matrix()
         np.random.shuffle(keypad_mat)
-        # select half the property sets
+        # select half the property positions
         prop_permutation = np.random.permutation(self.keypad_size.props_per_key)[: self.keypad_size.props_per_key // 2]
         key_permutation = np.random.permutation(self.keypad_size.numb_of_keys)
         # shuffle the selected property sets to new keys as a group