Automatically assign version to component based on reference (branch or tag) name if version not specified
When aggregating content (i.e., scanning repositories for files), automatically assign a component version if one is not specified in the component descriptor (antora.yml). The version should be based on the name of the current reference.
We may want to think about allowing a simple transformation of the reference name to the version number. For example, we many want to either extract a number from the reference name (e.g., v5.5), add characters to the reference name, or a combination of both. We'll need to figure out some way to express that transformation. Perhaps something like
version_pattern on the content source.