Add non-normative examples in the SLSA specifications

[Nikokrock]

At the meeting on the 11th of December, some of us suggested adding more examples (directly or indirectly) to the SLSA specification. These examples should be marked as non-normative inside the spec so that we can update them easily without following the usual SLSA spec publication process.

Any thoughts on that?

[arewm]

While I feel like adding additional examples will help comprehension and illuminate reasoning to extend beyond other situations (i.e. we can show the thought process behind the rationalizations), I would be cautious to add non-normative content to the specification as I foresee that these would likely increase in number and therefore lengthen the content length for the specification itself.

I wasn't on the call today, it looks like the topic of normative examples came up as well (in @lehors's topic on URIs in provenance format).

Is there some consideration of when we might need additional normative/non-normative examples?