Namespaces and versions (2022 02 transition)

Document what we are doing for namespaces and versions (2022-02 transition).

• Add namespace to all models in the playground.
  • "https://onedm.org/ecosystem/oma" for IPSO models.
  • "https://onedm.org/ecosystem/ocf" for OCF modes

For example

"namespace" : {
 "ocf" : "https://onedm.org/ecosystem/ocf"
},
"defaultNamespace" : "ocf"

(The ecosystem can also supply its own prefix, if it wants.) URIs are not intended to resolve, so any source of stable URIs can be used, including https://github.com/ecosystem1/randomname.

For versions, will use ecosystem extension for ecosystem models. For example

"info" : {
 "oma:version" : "1.1"
}