Documentation does not specify acrUsername and acrPassword are required to deploy the container

Hi,

I have started using this action, and from the documentation it was not clear that you are required to set up ACR credentials and apss them to the action. If you don't specify the action, the image cannot be pulled from ACR.

The minimal example in the docs is therefore insufficient for deploying a container.

https://github.com/marketplace/actions/azure-container-apps-build-and-deploy#minimal---build-application-image-for-container-app

I hope this can be addressed :)