License and Go modules

[breml]

Hi

Go modules expect the license file to resist in the same directory as the go.mod file. Since this is not the case in this repository, license information is not properly processed by tooling, that rely on Go modules like the official documentation (https://pkg.go.dev/github.com/rootless-containers/proto/go-proto) or google/go-licenses.

Please consider to copy the LICENSE file additionally to the go-proto sub folder.

Thanks!