Add documentation for Eventing Authorization (#6104)

* Add documentation for event authorization

* Add example for usage

* Switched from Trigger to Broker

* Add not to enable transport-encryption FF as well as a prerequisite

* Add more details on filters

* Move default auth mode doc up

* Add image for arch of example

* Fix how filters are applied

* Addressed review comments

* Add more details on rejection behavior

config/nav.yml

@@ -303,6 +303,7 @@ nav:
         - EventType auto creation: eventing/features/eventtype-auto-creation.md
         - Transport Encryption: eventing/features/transport-encryption.md
         - Sender Identity: eventing/features/sender-identity.md
+        - Authorization: eventing/features/authorization.md
         - Eventing with Istio: eventing/features/istio-integration.md
         - Cross Namespace Event Links: eventing/features/cross-namespace-event-links.md
       - FAQ: eventing/faq/README.md

config/redirects.yml

@@ -11,6 +11,7 @@ plugins:
       eventing/experimental-features/eventtype-auto-creation.md: eventing/features/eventtype-auto-creation.md
       eventing/experimental-features/transport-encryption.md: eventing/features/transport-encryption.md
       eventing/experimental-features/sender-identity.md: eventing/features/sender-identity.md
+      eventing/experimental-features/authorization.md: eventing/features/authorization.md
       eventing/features/new-trigger-filters.md: eventing/triggers/README.md
       eventing/broker/kafka-broker/kafka-configmap.md: eventing/configuration/kafka-channel-configuration.md
       eventing/broker/create-mtbroker.md: eventing/brokers/create-broker.md

docs/eventing/features/README.md

@@ -74,6 +74,7 @@ Knative Eventing:
 | [Knative reference mapping](kreference-mapping.md)            | `kreference-mapping`          | Provide mappings from a [Knative reference](https://github.com/knative/specs/blob/main/specs/eventing/overview.md#destination) to a templated URI.                                                                 | Alpha, disabled by default |
 | [Transport encryption](transport-encryption.md)               | `transport-encryption`        | Enables components to encrypt traffic using TLS by exposing HTTPS URL.                                                                                                                                             | Beta, disabled by default  |
 | [Sender Identity](sender-identity.md)                         | `authentication-oidc`         | Enables Eventing sources to send authenticated requests and addressables to require authenticated requests.                                                                                                        | Alpha, disabled by default |
+| [Authorization](authorization.md)                             | `default-authorization-mode`  | Enables Authorization for Eventing sinks. | Alpha, disabled by default |
 | [Eventing with Istio](istio-integration.md)                   | `istio`                       | Enables Eventing components to communicate with workloads in an Istio mesh.                                                                                                                                        | Beta, disabled by default  |
 | [Cross Namespace Event Links](cross-namespace-event-links.md) | `cross-namespace-event-links` | Enables subscriptions and triggers to refer to brokers and channels in different namespaces.                                                                                                                       | Alpha, disabled by default |