Update docs a bit in light of the new architectures

default.nix

@@ -1,5 +1,8 @@
 {
 
+  # TODO make this usable again! Add sane defaults for inputs, and allow for
+  # injecting a bootstrap file.
+
   pkgs,
   garage,
   selfRev,

docs/user/getting-started.md

@@ -3,7 +3,16 @@
 This document will guide you through the process of obtaining a cryptic-net
 binary and joining the network.
 
-NOTE currently only linux machines with amd64/x86_64 processors are supported.
+NOTE currently only linux machines with the following architectures are
+supported:
+
+- `x86_64` / `amd64`
+- `aarch64` / `arm64`
+- `armv7l` (Raspberry Pi)
+- `i686`
+
+(Only `x86_64` has been tested.)
+
 More OSs and architectures coming soon!
 
 ## Obtaining a cryptic-net Binary