add Kotlin library

Author: counters

README.md

@@ -54,4 +54,4 @@ Keyless encoding is also possible. [Picture](docs/static/Message_without_a_key.p
 Languages| Supported types | Url 
 ---|---|---
 Javascript|Integer, Double, ASCII|[counters/bip39-address-key2value.js](https://github.com/counters/bip39-address-key2value.js)
-Kotlin|Integer, ASCII|[comming soon](https://github.com/counters)
+Kotlin|Integer, ASCII|[counters/bip39-address-key2value.kt](https://github.com/counters/bip39-address-key2value.kt)