add nice output for ls

main.py

@@ -3,6 +3,7 @@
 import argparse
 from lib.DataStore import DataStore
 from lib.TimeSlot import TimeSlot
+from lib.ui import convert_to_table
 
 
 if __name__ == "__main__":
@@ -16,4 +17,4 @@ if __name__ == "__main__":
     ds = DataStore("data.json")
 
     if args.command == "ls":
-        print(ds.get_all_time_slots())
+        print(convert_to_table(ds.get_all_time_slots()))