Request a change links should go to the respective package repo

[susanev]

Clicking "Request a change" link when viewing the API Docs for a package navigates to pulumi-hugo (which in itself is incorrect as it should go to the registry). Instead, we should update it to go to the respective package's repo. For this we'll need the repo location for the package regardless of it is a first/third-party contributed package. This is something that's available in the schema and can be added to the metadata file so it can be accessed during site build from that file.