Add comment about how the cbindgen-vendor.tar.bz2 got created
We should add a comment about how the cbindgen vendor .bz2 file came into place (I forgot to do that in legacy/trac#30490 (moved)).
We should add a comment about how the cbindgen vendor .bz2 file came into place (I forgot to do that in legacy/trac#30490 (moved)).