${LOCATION} not used in one of the README commands

This:
```
gcloud run deploy ${SERVICE_NAME} \
  --image europe-west1-docker.pkg.dev/${PROJECT_ID}/internal-images/${SERVICE_NAME}:latest \
  --region=${LOCATION}
```

should be:
```
gcloud run deploy ${SERVICE_NAME} \
  --image ${LOCATION}-docker.pkg.dev/${PROJECT_ID}/internal-images/${SERVICE_NAME}:latest \
  --region=${LOCATION}
```