docs(web-dashboard): add data loading strategy card to architecture page

- Add a new card for the "Data Loading Strategy" in the CardGrid component
- Include a brief description and link to the data loading strategy page

Author: fulleni

src/content/docs/web-dashboard/architecture/index.mdx

@@ -16,4 +16,8 @@ The Flutter News App Web Dashboard is built upon a clean, scalable, and maintain
     An explanation of how navigation and routing are handled using go_router.
     [Read more →](/docs/web-dashboard/architecture/routing/)
   </Card>
+  <Card title="Data Loading Strategy" icon="cloud-download">
+    An explanation of the pre-fetching strategy for dropdown data.
+    [Read more &rarr;](/docs/web-dashboard/architecture/data-loading-strategy/)
+  </Card>
 </CardGrid>