Thanks to @domenkozar for implicitly reminding me that documentation is probably our biggest issue. And I'm a dumbass for contributing to that situation, so let's do better than that and document it. The current changes are only preparation for a bigger change coming real soon[TM] in Hydra and release-tools, so right now it's still a bit tedious to create custom channels. Signed-off-by: aszlig <aszlig@redmoonstudios.org>
To build the manual, you need Nix installed on your system (no need
for NixOS). To install Nix, follow the instructions at
    https://nixos.org/nix/download.html
When you have Nix on your system, in the root directory of the project
(i.e., `nixpkgs`), run:
    nix-build nixos/release.nix -A manual.x86_64-linux
When this command successfully finishes, it will tell you where the
manual got generated.