With this milestone, we're targeting the ability to extract and infer all key metadata for EAA:

• Visual adjustments with "feature": "displayTransformability"
• Nonvisual reading with "accessModeSufficient": "textual"
• Table of contents navigation with "feature": "tableOfContents"
• Heading navigation with "feature": "structuralNavigation"
• Print pagination with "feature": "pageNavigation" and "feature": "pageBreakMarkers"

This will require parsing HTML and CSS, which we haven't done (at least not much) in the Go Toolkit until now.