OPDS 2 : currentPage should have a min value

[llemeurfr]

currentPage of a feed is defined as "Indicates the current page number." and is an Integer.

Some developers start with 0, others with 1. It would be good to normalize the min value, my preference being 1.

[HadrienGardeur]

This could also be enforced in the JSON schema.

[HadrienGardeur]

I've just reviewed our JSON Schema and it uses an exclusive minimum of 0: https://github.com/opds-community/drafts/blob/master/schema/feed-metadata.schema.json#L42

This means that the minimum allowed value is actually 1. We could switch to minimum: 1 if it makes things clearer, is there any other change or addition that you would make @llemeurfr ?

[llemeurfr]

A clarification in the JSON schema is not sufficient. A mention in the specification is required to avoid mistakes.

Other properties may require the same level of precision in the specification, I didn't check the general case.