About the sample environment setting file

Thank you as always for your dedicated efforts.

On the fourth line of [openai-cua-sample-app/.env.example],
OPENAI_ORG = "org-123"
there should be no spaces on either side of the equal sign.

It would be better if you could tell me to run the command as follows:
```
set -a
source .env.example
set +a
```
