docs: Add API specification links to user guides

Add links to relevant API specification sections in documentation
guides to improve navigation between practical examples and detailed
API documentation.

This addresses issue #4347 by adding links to the following guides:
- HTTP feature guides (CORS, timeouts, method matching, etc.)
- gRPC and traffic splitting guides
- TLS configuration guide
- Getting started guide

All links follow the established pattern used in existing guides
and reference the correct v1 API types.

Fixes #4347

Signed-off-by: YASHMAHAKAL <[email protected]>

Author: YASHMAHAKAL

site-src/guides/getting-started/simple-gateway.md

@@ -8,8 +8,8 @@ This guide is a great place to start if you are new to Gateway API. It shows the
 {% include 'standard/simple-gateway/gateway.yaml' %}
 ```
 
-The Gateway represents the instantiation of a logical load balancer and the
-GatewayClass defines the load balancer template when users create a Gateway.
+The [Gateway](../../reference/spec.md#gateway.networking.k8s.io/v1.Gateway) represents the instantiation of a logical load balancer and the
+[GatewayClass](../../reference/spec.md#gateway.networking.k8s.io/v1.GatewayClass) defines the load balancer template when users create a Gateway.
 The example Gateway is templated from a hypothetical `example`
 GatewayClass, which is meant to be a placeholder and substituted by users. Here
 is a list of available
@@ -21,10 +21,10 @@ The Gateway listens for HTTP traffic on port 80. This particular GatewayClass
 automatically assigns an IP address which will be shown in the `Gateway.status`
 after it has been deployed. 
 
-Route resources specify the Gateways they want to attach to using `ParentRefs`. As long as 
+Route resources specify the Gateways they want to attach to using [`ParentRefs`](../../reference/spec.md#gateway.networking.k8s.io/v1.ParentReference). As long as 
 the Gateway allows this attachment (by default Routes from the same namespace are trusted),
 this will allow the Route to receive traffic from the parent Gateway. 
-`BackendRefs` define the backends that traffic will be sent to. More complex 
+[`BackendRefs`](../../reference/spec.md#gateway.networking.k8s.io/v1.HTTPBackendRef) define the backends that traffic will be sent to. More complex 
 bi-directional matching and permissions are possible and explained in other guides.
 
 The following HTTPRoute defines how traffic from the Gateway listener is routed

site-src/guides/grpc-routing.md

@@ -1,7 +1,7 @@
 # gRPC routing
 
 The [GRPCRoute resource](../api-types/grpcroute.md) allows you to match on gRPC traffic and
-direct it to Kubernetes backends. This guide shows how the GRPCRoute matches
+direct it to Kubernetes backends. This guide shows how the [GRPCRoute](../reference/spec.md#gateway.networking.k8s.io/v1.GRPCRoute) matches
 traffic on host, header, and service, and method fields and forwards it to different
 Kubernetes Services.
 

site-src/guides/http-cors.md

@@ -8,7 +8,7 @@ Cross-Origin Resource Sharing (CORS). CORS is a security feature that allows
 or denies web applications running at one domain to make requests for resources
 from a different domain.
 
-The `CORS` filter in an `HTTPRouteRule` can be used to specify the CORS policy.
+The [`CORS` filter](../reference/spec.md#gateway.networking.k8s.io/v1.HTTPCORSFilter) in an `HTTPRouteRule` can be used to specify the CORS policy.
 
 ## Allowing requests from a specific origin
 

site-src/guides/http-header-modifier.md

@@ -1,7 +1,7 @@
 # HTTP Header Modifiers
 
 [HTTPRoute resources](../api-types/httproute.md) can modify the headers of HTTP requests and the HTTP responses from clients.
-There are two types of [filters](../api-types/httproute.md#filters-optional) available to meet these requirements: `RequestHeaderModifier` and `ResponseHeaderModifier`.
+There are two types of [filters](../api-types/httproute.md#filters-optional) available to meet these requirements: [`RequestHeaderModifier`](../reference/spec.md#gateway.networking.k8s.io/v1.HTTPHeaderFilter) and [`ResponseHeaderModifier`](../reference/spec.md#gateway.networking.k8s.io/v1.HTTPHeaderFilter).
 
 This guide shows how to use these features.
 

site-src/guides/http-method-matching.md

@@ -4,7 +4,7 @@
     This feature is part of extended support. For more information on release channels, refer to our [versioning guide](../concepts/versioning.md).
 
 The [HTTPRoute resource](../api-types/httproute.md) can be used to match
-requests based on the HTTP method. This guide shows how to use this
+requests based on the [HTTP method](../reference/spec.md#gateway.networking.k8s.io/v1.HTTPRouteMatch). This guide shows how to use this
 functionality.
 
 ## Matching requests based on the HTTP method

site-src/guides/http-query-param-matching.md

@@ -4,7 +4,7 @@
     This feature is part of extended support. For more information on release channels, refer to our [versioning guide](../concepts/versioning.md).
 
 The [HTTPRoute resource](../api-types/httproute.md) can be used to match
-requests based on query parameters. This guide shows how to use this
+requests based on [query parameters](../reference/spec.md#gateway.networking.k8s.io/v1.HTTPQueryParamMatch). This guide shows how to use this
 functionality.
 
 ## Matching requests based on a single query parameter

site-src/guides/http-request-mirroring.md

@@ -3,8 +3,8 @@
 ???+ info "Extended Support Feature: HTTPRouteRequestMirror"
     This feature is part of extended support. For more information on release channels, refer to our [versioning guide](../concepts/versioning.md).
 
-The [HTTPRoute resource](../api-types/httproute.md) can be used to mirror
-requests to multiple backends. This is useful for testing new services with
+The [HTTPRoute resource](../api-types/httproute.md) can be used to [mirror
+requests](../reference/spec.md#gateway.networking.k8s.io/v1.HTTPRequestMirrorFilter) to multiple backends. This is useful for testing new services with
 production traffic.
 
 Mirrored requests will only be sent to one single destination endpoint

site-src/guides/http-timeouts.md

@@ -4,7 +4,7 @@
     This feature is part of extended support. For more information on release channels, refer to our [versioning guide](../concepts/versioning.md).
 
 The [HTTPRoute resource](../api-types/httproute.md) can be used to configure
-timeouts for HTTP requests. This is useful for preventing long-running requests
+[timeouts](../reference/spec.md#gateway.networking.k8s.io/v1.HTTPRouteTimeouts) for HTTP requests. This is useful for preventing long-running requests
 from consuming resources and for providing a better user experience.
 
 The `timeouts` field in an `HTTPRouteRule` can be used to specify a request

site-src/guides/tls.md

@@ -54,11 +54,11 @@ The use of `Terminate` on `TLSRoute` is available on `Extended` [Support Level].
 
 ## Downstream TLS
 
-Downstream TLS settings are configured using listeners at the Gateway level.
+Downstream TLS settings are configured using [listeners](../reference/spec.md#gateway.networking.k8s.io/v1.Listener) at the Gateway level.
 
 ### Listeners and TLS
 
-Listeners expose the TLS setting on a per domain or subdomain basis.
+Listeners expose the [TLS setting](../reference/spec.md#gateway.networking.k8s.io/v1.GatewayTLSConfig) on a per domain or subdomain basis.
 TLS settings of a listener are applied to all domains that satisfy the
 `hostname` criteria.
 
@@ -116,7 +116,7 @@ would be invalid.
 
 ## Upstream TLS
 
-Upstream TLS settings are configured using the `BackendTLSPolicy` attached to a
+Upstream TLS settings are configured using the [`BackendTLSPolicy`](../reference/spec.md#gateway.networking.k8s.io/v1.BackendTLSPolicy) attached to a
 `Service` via a target reference.
 
 This resource can be used to describe the SNI the Gateway should use to connect to the

site-src/guides/traffic-splitting.md

@@ -1,7 +1,7 @@
 # HTTP traffic splitting
 
 The [HTTPRoute resource](../api-types/httproute.md) allows you to specify
-weights to shift traffic between different backends. This is useful for
+[weights](../reference/spec.md#gateway.networking.k8s.io/v1.HTTPBackendRef) to shift traffic between different backends. This is useful for
 splitting traffic during rollouts, canarying changes, or for emergencies.
 The HTTPRoute`spec.rules.backendRefs` accepts a list of backends that a route
 rule will send traffic to. The relative weights of these backends define