feat: add initials variable from first, middle, and last names

Concatenate first characters of firstName, middleName, and lastName
to create initials string dynamically

Author: Tarawally

Sprint-1/1-key-exercises/2-initials.js

@@ -5,7 +5,6 @@ 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.
 
-let initials = ``;
+let initials = `${firstName[0] + middleName[0] + lastName[0]}`;
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
-