No -with-runtime tarball in release

[cguo5520]

Current Install steps:

Step 1: Install Darch
If you are on Arch Linux, you can install it from the AUR. Otherwise, head over to the GitHub Releases and download the Darch binaries. There are two packages you can download.

darch-amd64-with-runtime.tar.gz - Contains Darch, but with containerd and runc baked into it.
darch-amd64.tar.gz - Contains just Darch.

It doesn't look like releases come with runtime anymore. I think either the docs should be corrected or the runtime should be re-included.