Expand automated PR creation from issues

[caufieldjh]

Automated PR creation still needs:

• Sensitivity to which registry component should be updated (e.g., a new DataTopic needs to go in the container of data topics) #63
  This can be passed as part of the template, but doesn't need to be a user-submitted field.
• Parse the Description field - where it should go depends on the destination. Probably needs some minor validation, too.
• Add more fields to templates based off the schemas. Most should be optional
• Parse additional fields in the workflow script.
• Parse contributor details - fields are present, just need to parse