Create a type-safe string join utility which can be used like so:

const hyphenJoiner = join('-')
const result = hyphenJoiner('a', 'b', 'c'); // = 'a-b-c'

Or alternatively:

join('#')('a', 'b', 'c') // = 'a#b#c'

When we pass an empty delimiter (i.e '') to join, we should concat the strings as they are, i.e:

join('')('a', 'b', 'c') // = 'abc'

When only one item is passed, we should get back the original item (without any delimiter added):

join('-')('a') // = 'a'