Fix spec element URIs in Part 1

[ghobona]

• [ ] Replace the 4 occurrences of http://www.opengis.net/spec/ogcapi-common/1.0 with http://www.opengis.net/spec/ogcapi-common-1/1.0
• [ ] In Annex B.2 (Conformance Examples) the conformsTo example erroneously uses requirements class URIs. Only in Annex B.2, replace http://www.opengis.net/spec/ogcapi-common-1/1.0/req/ with http://www.opengis.net/spec/ogcapi-common-1/1.0/conf/

[ghobona]

An annotated copy of the document is at An annotated copy of the document is on the OGC Portal at https://portal.ogc.org/files/?artifact_id=100793