docs: remove unnecessary titles

Author: vahidvdn

content/fundamentals/discovery-service.md

@@ -2,9 +2,6 @@
 
 The `DiscoveryService` is a utility provided by `@nestjs/core` that allows developers to dynamically discover providers, controllers, and other metadata within a NestJS application. This can be particularly useful for building plugins, decorators, or features that rely on runtime introspection.
 
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-### Import Module & Service
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 Before using the `DiscoveryService`, you need to import the `DiscoveryModule` in your module:
 
 ```typescript
@@ -40,8 +37,6 @@ export class ExampleService {
 
 > info **Hint** The `DiscoveryService` class is imported from the `@nestjs/core` package.
 
-### Use Cases
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 #### Discovering Providers
 
 You can retrieve all registered providers in the application: