Better BullMQ integration documentation

I wasted some time on it, so I'll point out the missing things so people in the future won't waste time on it too:

1. Docker documentation lacking.
It does not explain how to adjust the flags locally.
It may be obvious to some, but it is worth noting.
In docker-compose file adding this line will adapt the instance for bullmq usage:
```
command: ["dragonfly", "--logtostderr", "--cluster_mode=emulated", "--lock_on_hashtags"]
```

2. BullMQ prefixes documentation only mention Queues.
https://www.dragonflydb.io/docs/integrations/bullmq#2-queue-naming-strategies

but obviously, it will not work if you won't add the prefix also on the `Worker`.
again, it may be obvious to some, but the last time I implemented BullMQ on my company was 2 years ago,
Mentioning the prefix must also be adjusted on the worker will save some time.

Start with the BullMQ integration page, especially “2. Queue naming strategies,” and the Docker Compose instructions. Document the command flags needed for local BullMQ use and clarify that the prefix must also be configured on Workers; done when both points are covered in the integration documentation.

Written by the indexing model from the issue text.