Where is the complete reference schema for `argoproj.io/v1alpha1`?

[l0b0]

If I have a YAML file which starts with apiVersion: argoproj.io/v1alpha1, what should I replace URL with in the # yaml-language-server: $schema=URL comment? There's no "v1alpha1" tag for https://github.com/argoproj/argo-schema-generator or https://github.com/argoproj/argo-workflows, so is the reference in some other repo?

https://argoproj.github.io/argo-workflows/ide-setup/ refers to the schema on the master branch, but I assume there's a specific commit I can refer to, rather than a moving target.