refactor: Move nix outside of .config dir

Technically not a config but a compose file, so I think it's better to
have outside of `.config` dir

nix/lib/darwin/libFixup.nix

@@ -0,0 +1,10 @@
+{ package, runCommandLocal, name }:
+
+runCommandLocal "${name}-symlink" {}
+  ''
+  dest="/usr/local/opt/${name}"
+
+  mkdir -p $dest
+
+  ln -sf "${package.out}/lib/" "$dest" && mkdir -p "$out" && touch "$out/${name}-done"
+  ''