chore: initial extension structure

extension/postcss.config.js

@@ -0,0 +1,10 @@
+/* eslint-disable no-undef */
+/**
+ * @type {import('postcss').ProcessOptions}
+ */
+module.exports = {
+  plugins: {
+    tailwindcss: {},
+    autoprefixer: {},
+  },
+};