Update container description on ghcr.io

While it is possible to update the README.md of npm packages and docker containers for the repo-specific Github Packages directly from the web interface, I could not find a possibility to do so for the organisation-wide container registry.

Q1: Is the README.md pulled from the repo kept up-to-date or does it need to be updated manually through github actions?
Q2: Is there a possibility to choose something else as the description instead of the README.md?

Thank you!