Provide source archive with submodules
GitHub's source archives don't include submodules. This can cause some confusion for people who just download it and try to build, running into errors about missing libraries. It's also a problem for package maintainers; for example, Debian packages are supposed to be able to be built from a tarball without access to the internet (and tarballs should ideally come from upstream instead of the maintainer making their own from a git checkout with submodules). Adding to each release your own source archive would solve these problems, and also allow the source to be included in your signed checksum file.