hswaw/signage: add development tip

Change-Id: I6dff93498ba2de959f1c7760a21c0972c2277037
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1336
Reviewed-by: q3k <q3k@hackerspace.pl>

hswaw/signage/README

@@ -9,6 +9,8 @@ Originally hosted on code.hackerspace.pl/informatic/love2d-signage, now in hsclo
 Building & Running
 ---
 
+Run the following in hscloud root:
+
     $ nix-build -A hswaw.signage.prod
     $ result/bin/signage
 
@@ -18,7 +20,11 @@ If the result doesn't run and complains about OpenGL not being available, try bu
 
 For non-NixOS systems you'll need something like `nixgl` to work around Nixpkgs-GL-on-Non-NixOS badness anyways.
 
+In order to run the app in more of a development environment with hot code reload and such use:
+
+    $ ENV=dev $(nix-build -A hswaw.signage.local.runtime --no-out-link)/bin/love hswaw/signage/
+
 Custom configs
 ---
 
-You can either modify config.lua and rebuild, or specify a custom config at runtime by settin gthe `SIGNAGE_CONFIG` environment variable.
+You can either modify config.lua and rebuild, or specify a custom config at runtime by setting the `SIGNAGE_CONFIG` environment variable.

hswaw/signage/default.nix

@@ -34,6 +34,8 @@
         EOF
         chmod +x $out/bin/signage
       '';
+
+      passthru.runtime = love12;
     };
   in signage;