Mention subscription setup difference between Apollo v2.x & v3.x

[exaucae]

Describe the issue

The documentation about subscriptions setup states that :

Fortunately, to make subscriptions work, we don't need to manually provide a transport layer that doesn't have constraints of HTTP and can do a push-based communication (WebSockets). The apollo-server package has built-in subscriptions support using websockets, so it works out of the box without any changes to our bootstrap config

This is outdated at least from Apollo ^3.x.x where built-in subscription support has been dropped. But there is no mention of that nuance in that particular section. As a result, subscription examples are misleading since they rely on Apollo 2.x.x .

A fix would be to :

• update that section to warn that from Apollo ^3.x.x there's no more built in support for subscription setup
• eventually add an example for apollo 3.x.x subscription setup in the docs

Are you able to make a PR that fix this? I'd love to, if pointed to the right place.

[victormazeli]

I have an issue publishing message from Redis CLI to graphql subscription using the graphql-Redis-subscription package. please any way to resolve this.

[AmitShimon198]

do you have a work around?

[MichalLytek]

The docs has been updated for the v2.0: https://github.com/MichalLytek/type-graphql/pull/1331/files#diff-5abc97b45da96920824409f599e3a905efc4242c25dea03280300b39c8be1b89

I also need to update the examples code.