remove references to "towards reproducibility" as that's not very
focused, and at that point readers will likely be familiar with the
concept such that they only need the reference, if anything
The cross compilation documentation is showing, at some point, two
variations on how to get a cross-compiled package out of Nixpkgs. Those
two versions are strictly equivalent (the only difference is what part
of the full attribute set paths is put in the variable named `pkgs`) and
don't really improve understanding - arguably, rather hurts it.
there have been discussions around migrating the platform description to a more structured representation like an attribute set (cannot find relevant issue for reference right now), and it is worth noting that this string encoding is fairly arbitrary.