Update sample instructions for ChatQnA to use published Docker images

[arun-gupta]

Docker images for different microservices are published at #361. All the sample instructions should be updated to use those images. "Building the Docker image" instructions are still useful for somebody who wants to tinker with the code and should be move to a different docuemnt.

[xiguiw]

@arun-gupta
After the images are published, we will update the instructions for ChatQnA to use published Docker images.

[xiguiw]

@arun-gupta
It seems the Docker images are published.
After I got the formal messages and verified it, I'll update the instructions.

Thank you!

[arun-gupta]

@xiguiw any updates on this? https://github.com/opea-project/GenAIExamples/tree/main/ChatQnA/docker/xeon#-build-docker-images is redundant

[xiguiw]

@xiguiw any updates on this? https://github.com/opea-project/GenAIExamples/tree/main/ChatQnA/docker/xeon#-build-docker-images is redundant
@arun-gupta Will update it next week.

When you mention it is redundant, do you mean pull docker image instead build it?
The docker image is specific or weekly build version, for daily update, build image from source code is needed.

[arun-gupta]

@xiguiw exactly, these instructions can be moved elsewhere and keep the primary set of instructions really simple by pulling a docker image. The instructions can use the latest tag. Other versions can be pulled by looking at different tags on Docker Hub.

[xiguiw]

@arun-gupta

Please help to review PR#762 for this issue.

There are platforms other than Xeon (Gauid,APIC) to be updated. And other GenAIExamples to be update.

[xiguiw]

Document updated.
All docker images could be download by run
docker compose up -d