Find a vowel at the begining and end with regular expression
// ^ => first item matches:
// () => stores matching value captured within
// [aeiou] => matches any of the characters in the brackets
// . => matches any character:
// + => for 1 or more occurrances (this ensures str length > 3)
// \1 => matches to previously stored match.
// \2 looks for matched item stored 2 instances ago
// \3 looks for matched item stored 3 ago, etc
// $ ensures that matched item is at end of the sequence
let re = /^([aeiou]).*\1$/i;
return re;
}