Add support for rendering AsciiDoc READMEs?

[chrysle]

What's the problem this feature will solve?

I've seen that AsciiDoc has become a popular markup language for project README files. Would you be potentially interested in maintaining support for a corresponding renderer, given the feature request in pypa/readme_renderer#205 is brought through?

Describe the solution you'd like

Adding AsciiDoc support to the warehouse README backend once the renderer supports it. Note that AsciiDoc does not have a dedicated content type, which could be seen as a downside.
Additional context

N/A

[di]

In addition to this requiring support in readme_renderer, we would also need to update the core metadata specifications to provide a Description-Content-Type value that would be a valid content type for AsciiDoc descriptions: https://packaging.python.org/en/latest/specifications/core-metadata/#description-content-type

Marking this blocked on pypa/readme_renderer#205

[CarrotManMatt]

This feature would be greatly appreciated!