#255 and #256: Core and SPARQL clean up - no more respec errors or warnings

- Editorial clean up to resolve and update references between the two new shacl docs.
- Changed RDF/SPARQL/TTL references to 1.2
- New CSS for all samples so that formatting and hyperlinks work again
- No normative changes (from what I can tell)
- Clean up of outdated stuff such as jQuery usage

Author: HolgerKnublauch