Challenge types:
Starts with AEnds with TContains E
Ends with "ING"Ends with "ER"Ends with "LY"
Ends with "ED"Ends with "TION"
Starts with "RE"Starts with "UN"Starts with "OUT"
No double lettersHas a double letter
Starts with a vowelEnds with a vowel
Exactly N lettersMore than N letters
Same first & last letterLetter appears twice