inserting the integration datetime as a description in the progress bar

Author: nilodna

parcels/_core/particleset.py

@@ -570,6 +570,7 @@ def execute(
                         next_output += outputdt
 
             if verbose_progress:
+                pbar.set_description("Integration time: " + str(time))
                 pbar.update((next_time - time) / np.timedelta64(1, "s"))
 
             time = next_time