Allow setting site_url

src/main/java/tk/draganczuk/url/App.java

@@ -36,6 +36,7 @@ public class App {
 			get("/all", Routes::getAll);
 			post("/new", Routes::addUrl);
 			delete("/:shortUrl", Routes::delete);
+			get("/siteUrl", Routes::siteUrl);
 		});
 
 		get("/:shortUrl", Routes::goToLongUrl);