Add snakeCaseString function for string conversion

Implement snakeCaseString function to convert strings to snake case and uppercase.

Author: Yonatanteklemariam

Sprint-2/3-mandatory-implement/2-cases.js

@@ -14,3 +14,7 @@
 // You will need to come up with an appropriate name for the function
 // Use the MDN string documentation to help you find a solution
 // This might help https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toUpperCase
+function snakeCaseString(str) {
+  return str.split(" ").join("_").toUpperCase();
+}
+console.log(snakeCaseString("lord of the rings"));