Add live demo section to README

Added a section for the live demo link to the README.

Author: flopez0294

README.md

@@ -8,6 +8,12 @@ A modern full-stack website built for Two Guys Auto Repair, a local automotive r
 
 ---
 
+## Live Demo
+
+Website available at:
+
+https://twoguysauto.onrender.com
+
 ## Overview
 
 This Two Guys Auto Repair Website is a modern web application built to help customers learn about available automotive services, contact the shop, and submit service inquiries through an easy-to-use web interface.