nested versions

[harlanlewis]

Use case
Our documentation covers discrete modules with independent versions. The documentation reader should be able to open version-specific documentation of each module, ideally via first class product concept. The current versions feature provides a global version switch, incompatible with modular versioning.

Current workarounds

• annotating page names with version number (optional collected in navigation groups per module)
• long pages, markdown headers to demarcate versions