Added challenge #1 section 04 code pen to the Challenges section of readme file.

Author: mirmak4

README.md

@@ -10,6 +10,10 @@
     -   Challenge #2: https://codepen.io/mirmak4/pen/oNQerZd
     -   Challenge #3: https://codepen.io/mirmak4/pen/PoxJNjQ
 
+-   Section 4 code pens:
+
+    -   Challenge #1: https://codepen.io/mirmak4/pen/dyQVRWe
+
 # Course Material and FAQ for "Build Responsive Real-World Websites with HTML and CSS"
 
 This repo contains starter files and final code for all sections and projects contained in the course.