README.md: Fix the credentials configuration
@@ -25,7 +25,7 @@ Finally, our docker rules needs authentication which is configured with the
```bash
gcloud components install docker-credential-gcr
-export DOCKER_CONFIG="$(docker-credential-gcr configure-docker | sed 's|/config.json ||')"
+export DOCKER_CONFIG="$(docker-credential-gcr configure-docker | sed -E 's|/config.json .*$||')"
```
You might want to permanently set your `DOCKER_CONFIG` environment, e.g. in your
