Update links to reference latest epub3 specification. (#123)

[wh1tewolfxx]

Update links to reference latest epub3 specification. (#123)

This is:

• a bug fix
• an enhancement

Related issue: #123

Description

Update W3 links referencing epub specification to latest version. (https://www.w3.org/TR/epub/)

• .github
• Documentation
• Source

Some section id's changed but most were reusable.

There was a deprecation from 3.2 -> 3.3 about defining collection types. Used best judgement to reference the correct sections for Schema/OPF/Collections/EpubCollection.cs.

See https://www.w3.org/TR/epub/#sec-defining-collection-types

Testing steps

Verify only comments should have been modified. No code changes.

[vers-one]

Thank you! I was actually planning to do this next week, so this is really helpful.

One minor suggestion: it would probably be better to use https://www.w3.org/TR/epub-33/ as the base URL, to avoid the documentation links pointing to EPUB 3.4 or EPUB 4 when they come out, since some of the links might get broken.

[vers-one]

Thank you! I checked all links and everything seems to be correct.

I replaced links for collection metadata and collection links with package metadata and package links respectively. It's unfortunate that the descriptions for those elements were removed in EPUB 3.3, even though the elements themselves are still valid within the specification (only the new collection roles were deprecated), but having the links to the package elements is probably the best option here.

[vers-one]

This will be released in version 3.4.0.