Update intra-doc links in API ref docs

[ianbotsf]

There's a bug in Dokka that prevents links from working across modules in the same repo: dokka#2679. A short-term workaround exists by enabling non-hierarchical project compatibility mode in gradle.properties:

kotlin.mpp.enableCompatibilityMetadataVariant=true

It has been indicated by JetBrains that this configuration will work around the issue on Dokka 1.7.10 but not on 1.7.20.