docs(api-server): update content and structure for clarity and comprehensiveness

- Rename 'API Server' to 'API Server: Introduction' for specificity
- Adjust description to mention Flutter News App toolkit instead of ecosystem
- Rename 'Getting Started' to 'Local Setup' for accuracy
- Add new 'Features' and 'Architecture' cards to enhance content structure
- Update card links to reflect new document structure
- Broaden 'How-To Guides' description to encompass various configuration tasks

Author: fulleni

src/content/docs/api-server/index.mdx

@@ -1,6 +1,6 @@
 ---
-title: API Server
-description: An overview of the high-performance Dart Frog backend that powers the Flutter News App ecosystem.
+title: 'API Server: Introduction'
+description: An overview of the high-performance Dart Frog backend that powers the Flutter News App toolkit.
 ---
 
 import { Card, CardGrid } from '@astrojs/starlight/components';
@@ -10,24 +10,28 @@ The API Server is the core backend component of the Flutter News App Toolkit. Bu
 It is designed to work seamlessly with the [Mobile Client](/docs/mobile-client/) and the [Web Dashboard](/docs/web-dashboard/).
 
 <CardGrid>
-  <Card title="Getting Started" icon="rocket">
+  <Card title="Local Setup" icon="rocket">
     Follow the local setup guide to get the server running on your machine.
-    [Read more &rarr;](/docs/api-server/getting-started/)
+    [Read more &rarr;](/docs/api-server/local-setup/)
   </Card>
   <Card title="Deployment" icon="cloud">
     Learn how to deploy the API server to a production environment.
     [Read more &rarr;](/docs/api-server/deployment/)
   </Card>
   <Card title="Features" icon="puzzle">
-    Explore the key features and architecture of the API server.
-    [Read more &rarr;](/docs/api-server/features/authentication/)
+    Explore the key features of the API server, from authentication to data management.
+    [Read more &rarr;](/docs/api-server/features/)
+  </Card>
+  <Card title="Architecture" icon="tree-structure">
+    Dive into the architectural patterns that make the server robust and maintainable.
+    [Read more &rarr;](/docs/api-server/architecture/)
   </Card>
   <Card title="API Reference" icon="open-book">
     A complete reference for all API endpoints and data models.
     [Read more &rarr;](/docs/api-server/reference/)
   </Card>
   <Card title="How-To Guides" icon="document">
     Practical guides for specific configuration and setup tasks.
-    [Read more &rarr;](/docs/api-server/guides/configure-environment-variables/)
+    [Read more &rarr;](/docs/api-server/guides/)
   </Card>
 </CardGrid>