added readme and some comments

milling_LUH_data.py

@@ -61,9 +61,8 @@ class milling_LUH(datasets.GeneratorBasedBuilder):
         )
 
     def _split_generators(self, dl_manager):
-
-		# TODO change data_dir if the folder name is changed  
         files_path = "data"
+        # TODO define train, test and validation splits. change only id_start and id_end
         return [
             datasets.SplitGenerator(
                 name=datasets.Split.TRAIN,