CanIUse-style client compliance table for IIIF Presentation clients

[tomcrane]

At IIIF AV meeting -

A machine-readable/computable notion of compliance is too difficult and puts too much burden on publishers. (IIIF/api#76)

But a community-maintained page/section of the site in the style of https://caniuse.com/ would be very useful.

Naming the features will be hard, and require lots of community participation.

[bvibber]

If the individual features described in the compatibility table can be machine-detected in a manifest, then could have a linting tool where you send it your manifest and it outputs a table of potential compatibility issues.

This would require linking the human-readable descriptions of features to machine-readable descriptions of how to detect they're in use, but wouldn't require the authors linting their manifests to know the machine-readable form themselves.

Automating compliance testing of features in viewers would be very difficult, so the compatibility table may need to be manually maintained.