docs(api-server): remove card grid from architecture page

- Deleted the CardGrid component and its contents from the architecture page
- Removed information about Dependency Injection and Middleware from the main content

Author: fulleni

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

@@ -6,14 +6,3 @@ description: Dive deeper into the architectural patterns and advanced concepts o
 import { Card, CardGrid } from '@astrojs/starlight/components';
 
 This section explores the core architectural patterns and advanced concepts that underpin the API server, providing a deeper understanding of its design.
-
-<CardGrid>
-  <Card title="Dependency Injection" icon="tree-structure">
-    Learn how the server manages and provides dependencies throughout the application.
-    [Read more &rarr;](/docs/api-server/advanced/dependency-injection)
-  </Card>
-  <Card title="Middleware" icon="layers">
-    Understand how middleware is used for cross-cutting concerns like authentication and logging.
-    [Read more &rarr;](/docs/api-server/advanced/middleware)
-  </Card>
-</CardGrid>