add tailwind and svelte-m3 to the frontend

frontend/postcss.config.cjs

@@ -0,0 +1,13 @@
+const tailwindcss = require("tailwindcss");
+const autoprefixer = require("autoprefixer");
+
+const config = {
+    plugins: [
+        //Some plugins, like tailwindcss/nesting, need to run before Tailwind,
+        tailwindcss(),
+        //But others, like autoprefixer, need to run after,
+        autoprefixer,
+    ],
+};
+
+module.exports = config;