add(timetabling): print out overlaps sorted order

timetabling/timetable-ics.py

@@ -104,11 +104,11 @@ for year in cals:
             overlap_entry = frozenset([event.name, overlap.name])
             if true_over and overlap_entry not in overlaps:
                 overlaps.add(overlap_entry)
-                overlaps_full.add(frozenset([
+                overlaps_full.add(tuple(sorted([
                     f"{event.name}@{event.begin.strftime('%a %H:%M')}",
                     f"{overlap.name}@{overlap.begin.strftime('%a %H:%M')}"
-                ]))
-    for overlap in overlaps_full:
+                ])))
+    for overlap in sorted(overlaps_full):
         print("OVERLAP:")
         for detail in overlap:
             print(" ", detail)