Fix assets path for production

Author: djhi

docs/js/ra-doc-exec.js

@@ -10,8 +10,8 @@ export const showTip = async () => {
     if (!tipElement) return;
 
     const [tips, features] = await Promise.all([
-        getContents('/assets/tips.md'),
-        getContents('/assets/features.md'),
+        getContents('./assets/tips.md'),
+        getContents('./assets/features.md'),
     ]);
     const all = tips.concat(features);