Register CNCF as persistent identifier namespace on the Web

Please consider registering CNCF as a persistent identifier namespace on the Web.

Web applications dealing with [Linked Data](https://en.wikipedia.org/wiki/Linked_data) often need URLs that are very stable. Registering CNCF as a persistent identifier namespace allows member projects to leverage the service. For example, CNCF projects publish their vocabulary at: https://w3id.org /cncf/, and potentially in machine readable format in future.

Example persistent identifiers namespaces:

https://w3id.org/cncf => https://www.cncf.io
https://w3id.org/cncf/glossary => https://glossary.cncf.io
https://w3id.org/cncf/glossary/IaaC => https://glossary.cncf.io/iaac # vocabulary, machine generated (CI pipeline)

The use cases and business value derives from [W3C Semantic web initiatives](https://www.w3.org/standards/semanticweb/), making CNCF data more accessible on the Semantic Web. W3ID.org is run by W3C Persistent Identifiers Committee and scales.

Procedure: Raise PR at https://github.com/perma-id/w3id.org#readme