feat(gs/home): Add rust development tools

rustup and rust-analyzer for now, but this will likely also have shell
aliases and the like

Change-Id: I7838e537a72600410205e018a0c86be1493a9ffe
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2207
Reviewed-by: glittershark <grfn@gws.fyi>
Tested-by: BuildkiteCI

users/glittershark/system/home/modules/development/rust.nix

@@ -0,0 +1,8 @@
+{ config, lib, pkgs, ... }:
+
+{
+  home.packages = with pkgs; [
+    rustup
+    rust-analyzer
+  ];
+}