Change correct answer value
Change correct answer value

According to the "What are GraphQL Subscriptions?" section, "Subscriptions are usually implemented with WebSockets". And there is no indication of the "@realtime" directive in the document.
This commit changes the correct answer value to 2 which is "Subscriptions are typically implemented via WebSockets".
howtographql/howtographql,howtographql/howtographql,howtographql/howtographql