Update past problem count to 20.

Co-authored-by: Raj Patel <raj454raj@gmail.com>

Author: MipsaPatel

modules/stopstalk_constants.py

@@ -53,7 +53,7 @@
 VIEW_ONLY_SUBMISSION_SITES = ["HackerEarth"]
 
 # Constants for recommendations
-PAST_PROBLEM_COUNT = 10
+PAST_PROBLEM_COUNT = 20
 DIFFICULTY_RANGE = 0.5
 RECOMMENDATION_COUNT = 10
 RECOMMENDATION_REFRESH_INTERVAL = 7