Ensure trailing slash to fix relative url's

index.html

@@ -9,6 +9,9 @@
 		<link rel="manifest" href="webmanifest.json" />
 		<link rel="stylesheet" href="style.css" />
 		<script>
+			if (!location.pathname.endsWith("/"))
+				location.pathname += "/";
+
 			function getLink() {
 				var phone = document.getElementById("phone").value.replace(/\D/g, "");
 				var message = document.getElementById("message-wrapper").open