Infer `accessibility` and `numberOfPages` metadata

[mickael-menu]

numberOfPages inference

When the metadata.numberOfPages property is missing from the manifest, use the --infer-page-count flag to fill it using the generated position list.

Accessibility metadata inference

rwp manifest can infer additional accessibility metadata when they are missing, with the --infer-a11y flag.

rwp manifest --infer-a11y publication.epub  | jq .metadata.accessibility

Inferred metadata

Key	Value	Inferred?
accessMode	auditory	If the publication contains a reference to an audio or video resource (inspect resources and readingOrder in RWPM)
accessMode	visual	If the publications contains a reference to an image or a video resource (inspect resources and readingOrder in RWPM)
accessModeSufficient	textual	If the publication is partially or fully accessible (WCAG A or above) Or if the publication does not contain any image, audio or video resource (inspect "resources" and "readingOrder" in RWPM) Or if the only image available can be identified as a cover
feature	displayTransformability	If the publication is fully accessible (WCAG AA or above) :warning: This property should only be inferred for reflowable EPUB files as it doesn't apply to other formats (FXL, PDF, audiobooks, CBZ/CBR).
feature	printPageNumbers	If the publications contains a page list (check for the presence of a pageList collection in RWPM)
feature	tableOfContents	If the publications contains a table of contents (check for the presence of a toc collection in RWPM)
feature	MathML	If the publication contains any resource with MathML (check for the presence of the contains property where the value is mathml in readingOrder or resources in RWPM)
feature	synchronizedAudioText	If the publication contains any reference to Media Overlays (TBD in RWPM)