How to publish Guides for Apple Maps

I’m noodling around Apple Maps in iOS and came across this section about exploring guides. Nothing there really interested me but I could imagine such a guide from a particular publisher of interest would. How are publishers chosen to be featured in Apple Maps? I presume it’s like search engines only a blessed finite few are selected to play this role. Is that the case with featured guides as well? Is there a way to share guides offline to a file or an iCloud link or something of the like?