started fresh from scratch
added interactive menu and linked it with option 1
added store_details? method returning true or false
added yes_or_no? method to use across various methods
added match method using regex to yes_or_no? method
added zero? method to cohort to check whether answer = 0 and redirect
added show_students method and linked with interactive menu
added print_header method & redirected show_students method if list is empty
extended show_students method to see whether user wants go back up to interactive menu
extended show_students method to see whether user wants go back up to interactive menu
fixed yes_or_no method to include nil response from user
merged file from from_scratch branch