Indy rb

Please accept this!!!
here is the general outline of a solution I was thinking about when I saw this:

```ruby
ending_map = {
  ["a", "e", "i", "o", "u"] => "foo",
  ["c", "q", "r"]           => "bar"
}

thing = "i"
ending = ending_map.find { |matchset, _| matchset.include?(thing) }.last
```

I can't tell if it's better.