Make module types explicit and convert some to ESM (#15964)

hassio/config.cjs

@@ -0,0 +1,9 @@
+const path = require("path");
+
+module.exports = {
+  // Target directory for the build.
+  buildDir: path.resolve(__dirname, "build"),
+  nodeDir: path.resolve(__dirname, "../node_modules"),
+  // Path where the Hass.io frontend will be publicly available.
+  publicPath: "/api/hassio/app",
+};