Restructure epub accessibility requirements

[mattgarrish]

Looking at the two requirements we have, they're actually a mix of different requirements under a common heading.

I'm thinking it would make sense to restructure these sections to better pull out the individual requirements, especially if we intend to expand on the requirements (whether we assign them as levels or keep as must/should/may).

For example, instead of one big "page navigation" section, we could restructure it as follows:

• Page Navigation
  • Overview - this would be the current explainer text in the "understanding" section
  • Applicability - this would be the prose explaining when we recommend including page navigation
  • Page Source - we'd define a summary, explainer and requirements for this and the next two criteria
  • Page List
  • Page Markers

The same could then be done for the media overlays section, where skippability, escapability and the nav doc requirements could be detailed separately.

Before I get into the actual restructuring of the document, though, does this make sense?

/cc @avneeshsingh @GeorgeKerscher @clapierre @gregoriopellegrino

[gregoriopellegrino]

Super fine for me, thanks!

[clapierre]

I agree great idea Matt!

[GeorgeKerscher]

I totally agree with this approach.