Add base infra to store assets

lib/music_library/assets.ex

@@ -0,0 +1,10 @@
+defmodule MusicLibrary.Assets do
+  alias MusicLibrary.Assets.Asset
+  alias MusicLibrary.Repo
+
+  def store(params) do
+    %Asset{}
+    |> Asset.changeset(params)
+    |> Repo.insert()
+  end
+end