This repository contains the source code for a Docker image that delegate the DocFX build process to a Docker container.
This way you only need to provide the DocFX metadata and content using a command like ADD [".", "docfx"] in your consuming Dockerfile.
An example can be found in the shared-kernel repository.
Note
Something happened with DocFX from version 2.78.0 (for ARM64 architecture). Not sure what, but it seems to be solved using --platform=$BUILDPLATFORM in the consuming Dockerfile.
For more information check out this discussion: What changes was applied to 2.78.x?