Source tarball on releases page missing submodules

[mapron]

At first, I need to delete github auto tarballs, as they broken. Second, I need to ship submodule source in some way: possible solutions:

1. just make source files with some script (one problem, is line feeds difference, probably have Windows feeds for everyone not a great solution).
2. add some script to pull dependencies after tarball extraction
3. autodetect this and disable zstd automatically, but won't work if I had obligatory submodules