title: How can I convert a camel case string to snake case and back in idiomatic Kotlin?
body: <p>Looking for code that will do conversions like this:
  "MyCamelCaseA" to "my_camel_case_a"
  "AMultiWordString" to "a_multi_word_string"
  "my_camel_case_a" to "myCamelCaseA" or "MyCamelCaseA" 
  "a_multi_word_string" to "aMultiWordString" or "AMultiWordString"</p>