exercise: implement string indexing for initials

Author: Grajales-K

Sprint-1/exercises/initials.js

@@ -4,3 +4,6 @@ let lastName = "Johnson";
 
 // Declare a variable called initials that stores the first character of each string.
 // This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution.
+
+const initial = firstName.charAt(0) + middleName.charAt(0) + lastName.charAt(0);
+console.log( `acronym = ${initial}`);