* changes: docs: linkify nix3-build mention in nix-build.md build: make internal-api-docs PHONY cleanup lookupFileArg add docstring to lookupFileArg add libcmd test for lookupFileArg
* changes: docs: linkify nix3-build mention in nix-build.md build: make internal-api-docs PHONY cleanup lookupFileArg add docstring to lookupFileArg add libcmd test for lookupFileArg