Update docstring in get_nnunet_trainer for better readability of supported trainer link

Author: SimoneBendazzoli93

monai/apps/nnunet/nnunet_bundle.py

@@ -83,7 +83,8 @@ def get_nnunet_trainer(
         The fold number or 'all' for cross-validation.
     trainer_class_name : str, optional
         The class name of the trainer to be used. Default is 'nnUNetTrainer'.
-        For a complete list of supported trainers: https://github.com/MIC-DKFZ/nnUNet/tree/master/nnunetv2/training/nnUNetTrainer/variants
+        For a complete list of supported trainers: 
+        https://github.com/MIC-DKFZ/nnUNet/tree/master/nnunetv2/training/nnUNetTrainer/variants
     plans_identifier : str, optional
         Identifier for the plans to be used. Default is 'nnUNetPlans'.
     use_compressed_data : bool, optional