Loose coupling with specs like Type Indexes, SAI, Solid-OIDC etc. #97

We discussed it during today's call meeting minutes

I would like to look for a way where WebID(Solid?) Profile has loose coupling with other specifications. I think the main question is about which spec depends on which other one. Currently, I would see the following approach but very likely we can find a better one:

• Solid-Profile depends on Web Identity and Discovery
• Solid-OIDC depends on Solid-Profile, requiring solid:oidcIssuer in the WebID Document (top security assertion)
• Solid Application Interoperability depends on Solid-Profile, requiring interop:hasAuthorizationAgent in the WebID Document (top security assertion)
• Type Indexes depend on Solid-Profile, requiring specific predicates and assigning specific security levels to them

I would imagine in the future there may be other specs that will want to depend on (extend) Solid-Profile specification. For example

• outcome resolving: [AuthN & AuthZ] Server side clients (apps) specification#504
• HttpSig Authentication for SoLiD
• someone might want to adapt Online Presence Ontology
• etc.

To support the discovery of those specs, Solid-Profile could maintain a listing of dependents, similar to https://solid.github.io/notifications/protocol#notification-channel-types

Also, a non-normative primer could provide developer-friendly examples of how various profiles work together with other specs depending on the solid profile.