Add a Package page links to outdated info about generating documentation

[dempseyatgithub]

The documentation callout on the Add a Package page (https://swiftpackageindex.com/add-a-package) has a More information here link to the blog post announcing documentation hosting.

The top of that page has the message:

The information in this blog post is superceded by our official documentation. Please refer to the documentation rather than this blog post.

The 'More information here' link should be updated to link to the official documentation.

[daveverwer]

Thanks @dempseyatgithub, I'll get this fixed 👍

[daveverwer]

Thanks for reporting this @dempseyatgithub! Fixed with #3247