MileStone-3:-Preliminary-Requirements.md

@@ -23,6 +23,7 @@ b.Test without clicking the coffee-add button (fail to add coffee)
 **User Stories and Accepting test:**
 
 As Jack, I want to be able to grab the coffee correctly by using the order number or  my phone number, which can make sure that I get the order I need.
+
 Tests:
 
 a.Test with a wrong order number (fail)