games/steam-sandbox: Bind factorio directory

It doesn’t use XDG directories, so all settings are reset and only some
aspects that are synced via Steam Cloud were kept.

users/simon/modules/games.nix

@@ -6,7 +6,7 @@ let
   steam-sandbox = pkgs.writeShellScriptBin "steam-sandbox" /* bash */ ''
     set -euo pipefail
     base_dir="''${XDG_DATA_HOME:-$HOME/.local/share}/steam-sandbox"
-    mkdir -p "$base_dir"/{.local/share,.steam,.config,data}
+    mkdir -p "$base_dir"/{.local/share,.steam,.config,.factorio,data}
     bubblewrap_args=(
         # sandboxing
         --unshare-all
@@ -60,6 +60,7 @@ let
         --bind "$base_dir/.local/share" "$HOME/.local/share"
         --bind "$base_dir/.steam" "$HOME/.steam"
         --bind "$base_dir/.config" "$HOME/.config"
+        --bind "$base_dir/.factorio" "$HOME/.factorio"
         --bind "$base_dir/data" "$HOME/data"
 
         # input