Add basic ServerName example & impl.

examples/ServerName.cpp

@@ -0,0 +1,24 @@
+#include "App.h"
+
+/* Note that uWS::SSLApp({options}) is the same as uWS::App() when compiled without SSL support */
+
+int main() {
+	/* Overly simple hello world app (SNI) */
+	uWS::SSLApp({
+	  .key_file_name = "../misc/key.pem",
+	  .cert_file_name = "../misc/cert.pem",
+	  .passphrase = "1234"
+	}).addServerName("localhost", {
+	  .key_file_name = "../misc/key.pem",
+	  .cert_file_name = "../misc/cert.pem",
+	  .passphrase = "1234"
+	}).get("/*", [](auto *res, auto *req) {
+	    res->end("Hello world!");
+	}).listen(3000, [](auto *token) {
+	    if (token) {
+		std::cout << "Listening on port " << 3000 << std::endl;
+	    }
+	}).run();
+
+	std::cout << "Failed to listen on port 3000" << std::endl;
+}