docs(throttler): clarify websocket throttler definitions

Clarify that websocket handleRequest overrides run for each configured throttler set so named throttlers keep separate counters.

Closes #3041

Author: iambeaukim

content/security/rate-limiting.md

@@ -216,6 +216,8 @@ There's a few things to keep in mind when working with WebSockets:
 
 > info **Hint** If you are using the `@nestjs/platform-ws` package you can use `client._socket.remoteAddress` instead.
 
+> info **Hint** When you configure [multiple throttler definitions](/security/rate-limiting#multiple-throttler-definitions), `handleRequest()` runs once for each throttler set. Use the `throttler.name` from `ThrottlerRequest` when generating the storage key and when reporting the `ThrottlerLimitDetail`, as shown above, so each named throttler tracks its own limit.
+
 #### GraphQL
 
 The `ThrottlerGuard` can also be used to work with GraphQL requests. Again, the guard can be extended, but this time the `getRequestResponse` method will be overridden