Update Display of accessibility metadata following Guide 2.0

[gautierchomel]

User Experience Guide for accessibility metadata 2.0 first public draft is available. The set of documents includes:

• Principles document
• ONIX metadata Techniques
• EPUB Accessibility metadata Techniques

Thorium pioneered the display of such information in a reading system, but the way it is presented is now outdated.

We should implement this significant update so it can be used to test and provide feedback.

[gautierchomel]

For implementation & testing:

• Exploded EPUB
• Packed EPUB
• OPDS

[gautierchomel]

Also, there is a localization JSON available from W3C: https://github.com/w3c/publ-a11y/blob/main/UX-Guide-Metadata/draft/localizations/en-US/display_guide_vocabulary_w3c_en-US.json

Future localizations to be added.

It is intended to work with the techniques documents (Code IDs of the techniques are Keys of the JSON).

Example:
THEN display "Appearance can be modified". Is refering to "visual-adjustments-modifiable": {

A display of JSON values is available at https://rawcdn.githack.com/w3c/publ-a11y/91141c948fcb1b40ed13dc0b58567307a44474a4/UX-Guide-Metadata/draft/localizations/index.html

[gautierchomel]

Thorium should use Compact sentences with no titles for categories and keep things as simple as a list.

Example:

• Appearance can be modified
• Not fully readable in read-aloud and braille
• Navigation by table of contents, index, landmarks, and page list
• This publication meets minimum accessibility standards