Move assets to a separate mod

lignumis/data.lua

@@ -22,8 +22,13 @@ Lignumis = {
     lab_blacklist = {
         "wood-lab", -- Lignumis
         "cerys-lab" -- Cerys
+    },
+
+    assets = "__lignumis-assets__/"
 }
-}
+
+Lignumis.graphics = Lignumis.assets .. "graphics/"
+Lignumis.sound = Lignumis.assets .. "sound/"
 
 if not settings.startup["lignumis-technology-progression"].value then
     Lignumis.science_pack_whitelist = {}