Proposal: Using HTML's nav element as manifest

Hi Everyone,

Benjamin and I have been working on a proposal to use HTML's <nav> element
as a web publication manifest:

https://github.com/dauwhe/html-first

TL:DR define the primary resources of a WP to be the files referenced in
the first <nav> element of an "index" file. This file would also host WP
metadata.

We feel this approach has many benefits:

1. Human-focused. User agents need a list of primary resources and their
default ordering, but so do actual users. Most web publications would
benefit from a human-readable table of contents. TOCs are crucial for
accessibility.

2. Simplicity. Given the broad need for a TOC, using that as manifest is a
straightforward way to avoid duplication (as in EPUB's
nav/manifest/spine/ncx). And we've discovered a huge benefit, as we don't
need a list of secondary resources to facilitate offline caching via
service workers (see the demo books)!

3. Ubiquity. Everyone in the web space is already familiar with HTML, and
there is a large and mature ecosystem around authoring, rendering, and
validating HTML.

4. Expressiveness. HTML's language and styling support allows for a richer
experience for humans.

5. Progressive enhancement. Existing web user agents know what to do with
HTML.

6. A Path to the future. Every EPUB3 has a nav document. Many "web books"
already use such a design pattern.

Note we've created a couple of demo books that work offline, based on the
HTML manifest.

Thanks,

Benjamin and Dave

P.S. Dave  will be on holiday Aug 17-25, so some responses may be delayed