Set the Category, OS, and Architecture attributes of the Docker Hub repositories

[MichaelSimons]

MCR now supports setting these attributes via it's repo YAML. Setting these attributes will help the UX for users exploring the DH content.

Related to dotnet/docker-tools#527 and dotnet/docker-tools#526

See the MCR documentation (internal Microsoft link) for details on how to specify the attributes in the MCR repo YAML.

[MichaelSimons]

The architecture and OS platform do not flow to DH correctly. MCR is working to resolve the issue.