chore: fix too-short meta descriptions for better seo

fern/products/api-def/grpc-pages/services/streaming.mdx

@@ -1,6 +1,6 @@
 ---
 title: Streaming
-subtitle: Implement server streaming, client streaming, and bidirectional streaming with gRPC
+description: Learn how to implement server streaming, client streaming, and bidirectional streaming in gRPC for real-time communication and efficient data transfers.
 ---
 
 gRPC supports four types of service methods: unary, server streaming, client streaming, and bidirectional streaming. Streaming enables efficient real-time communication and large data transfers.

fern/products/api-def/openapi-pages/extensions/overview.md

@@ -1,6 +1,6 @@
 ---
 title: Overview of OpenAPI extensions
-description: Learn about Fern's OpenAPI extensions
+description: Learn about OpenAPI extensions in Fern. Customize authentication, SDK methods, versioning, and more for better API specs.
 ---
 Fern supports a variety of OpenAPI extensions that enhance your API specification and generate higher-quality SDKs. 
 

fern/products/api-def/openapi-pages/extensions/retries.mdx

@@ -1,6 +1,6 @@
 ---
 title: Retry behavior
-subtitle: Configure retry behavior for endpoints using `x-fern-retries` extension
+description: Control API retry logic with x-fern-retries extension. Configure endpoint-level retry behavior and disable retries for payment processing and order creation.
 ---
 
 <Callout intent="info">