docs: Make a fix in the main README.md of the ChatQnA.

The source of the set_env.sh from the root folder of the example does not work, need to cd into each of the hardware option (intel/nvidia).

Author: kendall1997

ChatQnA/README.md

@@ -68,13 +68,16 @@ To set up environment variables for deploying ChatQnA services, follow these ste
 
    ```bash
    # on Gaudi
-   source ./docker_compose/intel/hpu/gaudi/set_env.sh
+   cd GenAIExamples/ChatQnA/docker_compose/intel/hpu/gaudi/
+   source ./set_env.sh
    export no_proxy="Your_No_Proxy",chatqna-gaudi-ui-server,chatqna-gaudi-backend-server,dataprep-redis-service,tei-embedding-service,retriever,tei-reranking-service,tgi-service,vllm-service,guardrails
    # on Xeon
-   source ./docker_compose/intel/cpu/xeon/set_env.sh
+   cd GenAIExamples/ChatQnA/docker_compose/intel/cpu/xeon/
+   source ./set_env.sh
    export no_proxy="Your_No_Proxy",chatqna-xeon-ui-server,chatqna-xeon-backend-server,dataprep-redis-service,tei-embedding-service,retriever,tei-reranking-service,tgi-service,vllm-service
    # on Nvidia GPU
-   source ./docker_compose/nvidia/gpu/set_env.sh
+   cd GenAIExamples/ChatQnA/docker_compose/nvidia/gpu
+   source ./set_env.sh
    export no_proxy="Your_No_Proxy",chatqna-ui-server,chatqna-backend-server,dataprep-redis-service,tei-embedding-service,retriever,tei-reranking-service,tgi-service
    ```