updated readme file with usage

README.md

@@ -129,6 +129,57 @@ https://unpkg.com/subscriptions-transport-ws@VERSION/browser/client.js
 
 > Replace VERSION with the latest version of the package.
 
+### Use it with GraphiQL
+
+You can use this package's power with GraphiQL, and subscribe to live-data stream inside GraphiQL.
+
+If you are using the latest version of `graphql-server` flavors (`graphql-server-express`, `graphql-server-koa`, etc...), you already can use it! Make sure to specify `subscriptionsEndpoint` in GraphiQL configuration, and that's it!
+
+For example, `graphql-server-express` users need to add the following:
+
+```js
+app.use('/graphiql', graphiqlExpress({
+  endpointURL: '/graphql',
+  subscriptionsEndpoint: `YOUR_SUBSCRIPTION_ENDPOINT_HERE`,
+}));
+```
+
+If you are using older version, or another GraphQL server, start by modifying GraphiQL static HTML, and add this package and it's fetcher from CDN:
+
+```html
+    <script src="//unpkg.com/subscriptions-transport-ws@0.5.4/browser/client.js"></script>
+    <script src="//unpkg.com/graphiql-subscriptions-fetcher@0.0.2/browser/client.js"></script>
+```
+
+Then, create `SubscriptionClient` and define the fetcher:
+
+```js
+let subscriptionsClient = new window.SubscriptionsTransportWs.SubscriptionClient('SUBSCRIPTION_WS_URL_HERE', {
+  reconnect: true
+});
+let myCustomFetcher = window.GraphiQLSubscriptionsFetcher.graphQLFetcher(subscriptionsClient, graphQLFetcher);
+```
+
+> `graphQLFetcher` is the default fetcher, and we use it as fallback for non-subscription GraphQL operations.
+
+And replace your GraphiQL creation logic to use the new fetcher:
+
+```js
+ReactDOM.render(
+  React.createElement(GraphiQL, {
+    fetcher: myCustomFetcher, // <-- here
+    onEditQuery: onEditQuery,
+    onEditVariables: onEditVariables,
+    onEditOperationName: onEditOperationName,
+    query: ${safeSerialize(queryString)},
+    response: ${safeSerialize(resultString)},
+    variables: ${safeSerialize(variablesString)},
+    operationName: ${safeSerialize(operationName)},
+  }),
+  document.body
+);
+```
+
 # API
 
 ## SubscriptionClient