chore: prep tailwind for theming

tailwind.config.js

@@ -1,7 +1,14 @@
 export default {
   content: ["./src/**/*.{ts,tsx}", "./src/renderer/**/*.html"],
+  darkMode: ["class", '[data-theme="dark"]'],
   theme: {
-    extend: {},
+    extend: {
+      colors: {},
+      spacing: {},
+      fontSize: {},
+      borderRadius: {},
+      boxShadow: {},
+    },
   },
   plugins: [],
 }