Enhance README with Smart Test Selection details

Added information about BrowserStack's Smart Test Selection AI Agent and its benefits.

Author: Dave3130

README.md

@@ -1,2 +1,10 @@
 # test-selection-demo-test-browserstack
 Test Selection Demo Test Browserstack
+
+# BrowserStack Smart Test Selection AI Agent
+---
+## What is Smart Test Selection?
+BrowserStack's Smart Test Selection Agent uses AI to identify and run only the tests impacted (or likely to fail) by your code changes, reducing build time and cost by up to 50%. This demo uses the BrowserStack Java SDK with TestNG.
+
+## Introduction
+This repository demonstrates BrowserStack's Smart Selection AI Agent. For demo steps, checkout branch `tesng-automate` and follow the readme