add ssl guide ref

guide/src/qs_13.md

@@ -26,9 +26,9 @@ fn main() {
     let pkcs12 = Pkcs12::from_der(&pkcs12).unwrap().parse("12345").unwrap();
 
     HttpServer::new(
-        Application::new("/")
-            .resource("/index.html", |r| r.f(index))
-        .serve_tls::<_, ()>("127.0.0.1:8080", pkcs12).unwrap();
+        || Application::new()
+            .resource("/index.html", |r| r.f(index)))
+        .serve_ssl::<_, ()>("127.0.0.1:8080", pkcs12).unwrap();
 }
 ```
 

guide/src/qs_3_5.md

@@ -25,6 +25,40 @@ Server create separate application instance for each created worker. Application
 is not shared between threads, to share state `Arc` could be used. Application state
 does not need to be `Send` and `Sync` but application factory must be `Send` + `Sync`.
 
+## SSL
+
+There are two `tls` and `alpn` features for ssl server. `tls` feature is for `native-tls`
+integration and `alpn` is for `openssl`.
+
+```toml
+[dependencies]
+actix-web = { git = "https://github.com/actix/actix-web", features=["alpn"] }
+```
+
+```rust,ignore
+use std::fs::File;
+use actix_web::*;
+
+fn main() {
+    let mut file = File::open("identity.pfx").unwrap();
+    let mut pkcs12 = vec![];
+    file.read_to_end(&mut pkcs12).unwrap();
+    let pkcs12 = Pkcs12::from_der(&pkcs12).unwrap().parse("12345").unwrap();
+
+    HttpServer::new(
+        || Application::new()
+            .resource("/index.html", |r| r.f(index)))
+        .serve_ssl::<_, ()>("127.0.0.1:8080", pkcs12).unwrap();
+}
+```
+
+Note on *HTTP/2* protocol over tls without prior knowlage, it requires
+[tls alpn](https://tools.ietf.org/html/rfc7301). At the moment only
+`openssl` has `alpn ` support.
+
+Please check [example](https://github.com/actix/actix-web/tree/master/examples/tls) 
+for concrete example.
+
 ## Keep-Alive
 
 Actix can wait for requesta on a keep-alive connection. *Keep alive*