Adds summary documention for the checker function

Author: omega-coder

checker.py

@@ -25,7 +25,8 @@ def check_timetable_validity(timetable_path,
                              dates,
                              events_freq=1,
                              max_events=None):
-    """[summary]
+    """Converts event form a FET csv generated timetable file to google calendar events, and checks if any erors are\
+         present 
     
     Args:
         timetable_path (str): path to the timetable csv file generated by FET.