Add a missing requirement to choose the t-shirt color

Author: Diana Ausiejute

Form-Controls/index.html

@@ -26,7 +26,7 @@ <h1>Product Pick</h1>
 
         <fieldset>
           <legend>T-shirt Color</legend>
-          <input type="radio" id="blue" name="color" value="B" />
+          <input type="radio" id="blue" name="color" value="B" required />
           <label for="blue">Blue</label><br />
 
           <input type="radio" id="green" name="color" value="G" />