Best practices for links

[leonardr]

There are a number of links it would be useful to have in the Authentication For OPDS document, in its role as the machine-readable "front page" of an OPDS server. In the spec we can use SHOULD to create an expectation that A4OPDS documents ought to contain, if possible, links to these resources:

• The bookshelf feed
• The user profile
• The homepage of the organization running the OPDS server
• The root feed of the OPDS server
• An icon for the OPDS server