docs(subscriptions): restore redis example link

Author: MichalLytek

docs/subscriptions.md

@@ -207,6 +207,5 @@ However, beginning in Apollo Server 3, subscriptions are not supported by the "b
 
 See how subscriptions work in a [simple example](https://github.com/MichalLytek/type-graphql/tree/master/examples/simple-subscriptions). You can see there, how simple is setting up GraphQL subscriptions using `graphql-yoga` package.
 
-<!-- FIXME: restore when redis example is upgraded -->
-<!-- For production usage, it's better to use something more scalable like a Redis-based pubsub system - [a working example is also available](https://github.com/MichalLytek/type-graphql/tree/master/examples/redis-subscriptions).
-However, to launch this example you need to have a running instance of Redis and you might have to modify the example code to provide your connection parameters. -->
+For production usage, it's better to use something more scalable like a Redis-based pubsub system - [a working example is also available](https://github.com/MichalLytek/type-graphql/tree/master/examples/redis-subscriptions).
+However, to launch this example you need to have a running instance of Redis and you might have to modify the example code to provide your connection parameters.