'Random Background Color Changer' docs: README.md update main README.md (variation_2)

Author: AndriiKot

README.md

@@ -10,6 +10,27 @@ In this project, you will help CamperBot build a random background color changer
   <summary>
     <h4>Description of the Tasks</h4>
   </summary>
+    <details>
+    <summary>
+      <h5>Step 4</h5>
+    </summary>
+    <p>
+        CamperBot is finished with building out the
+        getRandomIndex function and it is working as expected. But now they are running into this issue
+        when trying to create a reference to the <code>body</code> element in the DOM:
+    </p>
+    <p>
+        <code>Uncaught TypeError: document.queryselector is not a function</code>
+    </p>
+    <p>
+        A TypeError means that the code is trying to perform
+        an operation on a value that is not of the expected type.
+    </p>
+    <p>
+        Fix the TypeError by updating the document.queryselector
+        method to the correct method name that selects an element from the DOM.
+    </p>
+  </details>
   <details>
     <summary>
       <h5>Step 5</h5>