Your README doesn't indicate that it only supports OSX. The "update" command downloads the osx build and replaces a hard-coded system install location.
Aside from the "create" command setting up an opinionated project structure, to me is seems like the build, mod, vendor logic just thinly wraps calls to the Go tool equivalent commands. What is it really doing that the current go tool doesn't handle? I thought go module support works in any location already.