Move all examples to their own crates (#201)

This makes it much clearer which dependencies each example has.

examples/websockets/assets/script.js

@@ -0,0 +1,9 @@
+const socket = new WebSocket('ws://localhost:3000/ws');
+
+socket.addEventListener('open', function (event) {
+    socket.send('Hello Server!');
+});
+
+socket.addEventListener('message', function (event) {
+    console.log('Message from server ', event.data);
+});