Update db_type assignment in app.py for improved clarity in contest type handling

- Changed the assignment of db_type for 'Showdown' from 'sd' to 'showdown', enhancing code readability and consistency.
- Maintained existing functionality while improving the clarity of contest type definitions in the data retrieval process.

app.py

@@ -36,7 +36,7 @@ def grab_contest_player_info(db, sport, type, contest_date):
     if type == 'Classic':
         db_type = 'reg'
     elif type == 'Showdown':
-        db_type = 'sd'
+        db_type = 'showdown'
     collection = db[f'{sport}_{db_type}_player_info']
     cursor = collection.find()