Add websocket doc

docs/websockets.md

@@ -0,0 +1,35 @@
+# Using Websockets
+
+Using Websockets is super easy! By nature Websockets are a bit different than standard Http Request/Response lifecycle.
+
+You can easily create a websocket handler which matches the route of `ws://host:port/route. You can create more than 1 websocket handler
+with different routes.
+
+```ruby
+  ws "/" do |socket|
+
+  end
+
+  ws "/route2" do |socket|
+
+  end
+```
+
+Let's access the socket and create a simple echo server.
+
+```ruby
+  ws "/" do |socket|
+    # Send welcome message to the client
+    socket.send "Hello from Kemal!"
+
+    # Handle incoming message and echo back to the client
+    socket.on_message do |message|
+      socket.send "Echo back from server #{message}"
+    end
+
+    # Executes when the client is disconnected. You can do the cleaning up here.
+    socket.on_close do
+      puts "Closing socket"
+    end
+  end
+```