update index.html

docs/index.html

@@ -239,7 +239,8 @@
               <!-- Closing -->
               <div class="text-center" style="margin-top: 70px">
                 <a href="https://github.com/frappe/charts/archive/master.zip"><button class="large blue button">Download</button></a>
-                <p class="mt-2"><a href="https://github.com/frappe/charts" target="_blank">View on GitHub</a></p>
+                <p style="margin-top: 3rem;margin-bottom: 1.5rem;"><a href="https://github.com/frappe/charts" target="_blank">View on GitHub</a></p>
+                <p style="margin-top: 1rem;"><iframe src="https://ghbtns.com/github-btn.html?user=frappe&repo=charts&type=star&count=true" frameborder="0" scrolling="0" width="94px" height="20px"></iframe></p>
                 <p>License: MIT</p>
               </div>
             </div>