add rout ws

demo/routes.py

@@ -3,5 +3,10 @@ import aiohttp
 
 
 def setup_routes(app):
-  app.router.add_routes([aiohttp.web.get('/', frontend.index), aiohttp.web.post('/submit', frontend.button_clicked)])
+  app.router.add_routes([aiohttp.web.get('/index.html', frontend.index),
+                         aiohttp.web.post('/submit', frontend.button_clicked),
+                         aiohttp.web.get('/index_2.html', frontend.index_2),
+                         aiohttp.web.get('/ws', frontend.websocket_handler)
+                        ]
+                        )