docs(types): oci type repositry_url must be percent encoding

[masahiro331]

OCI specification

repository_url: A repository URL where the artifact may be found, but not intended as the only location. This value is encouraged to identify a location the content may be fetched

pkg:oci/static@sha256:<digest>?repository_url=gcr.io/distroless/static&tag=latest

qualifiers specification

A value must be a percent-encoded string

Must repository_url be percent-encoded?

[stevespringett]

@pombredanne The test suite, in this spec repo and used by all implementations, do not have repository_url encoded.

[johnmhoran]

Hi @masahiro331 and thank you for your PR. I see that although most of the proposed changed PURLs are for qualifiers values, one is for a subpath value. My sense is that the '/' in a qualifier value must be percent-encoded, but the '/' in a subpath value must not be encoded. To enable us to tackle these 2 PURL components individually, could you please replace this PR 150 with two separate PRs?