I have more information. After stumbling around and around the web Portal looking for anything related to documentation I noticed a *Developer portal* icon. The help indicates that this is the magic place where API documentation is managed, but clicking the Publish button does nothing. 15 minutes later I discover that the feature is not available on the consumption plan I chose.
The Basic production plan is ~$200/month which WAY beyond our tolerance levels. Our API usage is so low that the consumption plan would have been ideal, but in a Catch-22 there is documentation available. Now I'll just delete the APIM feature and forget it. *GK*
