(#1) - WebPack bundling of JS and CSS (#1)

This work was done with Claude.

Added bundling of CSS & JS with WebPack. This also means minimization.

---------

Co-authored-by: Martin Slachta <martin.slachta@outlook.com>
Reviewed-on: #1

webpack.config.js

@@ -0,0 +1,17 @@
+const defaultConfig = require('@wordpress/scripts/config/webpack.config');
+
+const defaultEntry = defaultConfig.entry;
+
+module.exports = {
+    ...defaultConfig,
+    entry: async () => {
+        const entries = typeof defaultEntry === 'function'
+            ? await defaultEntry()
+            : defaultEntry;
+        return {
+            ...entries,
+            client: './src/client.js',
+            admin:  './src/admin.js',
+        };
+    },
+};