Add documentation output options
Litbuild can generate shell scripts that execute a build process, and should be able to alternatively generate documentation for that build.
The script generated by the tool should be considered an ephemeral artifact, usable at the moment it is generated on the system where it is generated, but not necessarily usable again thereafter. The same would be true for documentation outputs.
Not sure what the best output format would be. Possibly docbook XML, since there are well-established documentation toolchains for XML.