Initial: Standalone mixer app with MixerPage, scene management, WS proxy

frontend/node_modules/postcss/lib/stringify.d.ts

@@ -0,0 +1,9 @@
+import { Stringifier } from './postcss.js'
+
+interface Stringify extends Stringifier {
+  default: Stringify
+}
+
+declare let stringify: Stringify
+
+export = stringify