Add rustler to mix project properly

Author: RoyalIcing

mix.exs

@@ -7,10 +7,11 @@ defmodule ComponentsGuide.MixProject do
       version: "0.1.0",
       elixir: "~> 1.12",
       elixirc_paths: elixirc_paths(Mix.env()),
-      compilers: [:phoenix, :gettext] ++ Mix.compilers(),
+      compilers: [:phoenix, :gettext, :rustler] ++ Mix.compilers(),
       start_permanent: Mix.env() == :prod,
       aliases: aliases(),
-      deps: deps()
+      deps: deps(),
+      rustler_crates: rustler_crates()
     ]
   end
 
@@ -79,4 +80,13 @@ defmodule ComponentsGuide.MixProject do
       ]
     ]
   end
+
+  defp rustler_crates do
+    [
+      io: [
+        path: "native/componentsguide_rustler_math",
+        mode: if(Mix.env() == :prod, do: :release, else: :debug)
+      ]
+    ]
+  end
 end