feat: ✨ Finish FirstUpper

Iteration/Iterations.cs

@@ -58,8 +58,17 @@ public class Iterations
         return false;
     }
 
-    public static bool FirstUpper(string s, string sub)
+    public static string FirstUpper(string s)
     {
-        return true;
+        string phrase = s;
+        string[] word = s.Split(' ');
+        string result = String.Empty;
+        foreach (var element in word)
+        {
+            string first = element.Substring(0, 1);
+            result += first.ToUpper() + element.Substring(1) + " ";
+        }
+
+        return result.TrimEnd();
     }
 }