docs: Add page descriptions (#1056)

* docs: Add page descriptions

* docs: Include the resource requests partial

* docs: Fix the resource requests include

Author: lfrancke

docs/modules/kafka/pages/reference/commandline-parameters.adoc

@@ -1,4 +1,5 @@
 = Command line parameters
+:description: Command-line parameters the Stackable operator for Apache Kafka accepts, with their default values and usage examples.
 
 This operator accepts the following command line parameters:
 

docs/modules/kafka/pages/reference/crds.adoc

@@ -1,3 +1,4 @@
 = CRD Reference
+:description: CRD reference for the Stackable operator for Apache Kafka on the Stackable Hub, covering every field, default and API version.
 
 Find all CRD reference for the Stackable Operator for Apache Kafka at: {crd-ref}{crd-ref-release}&operator=kafka-operator.

docs/modules/kafka/pages/reference/discovery.adoc

@@ -3,6 +3,7 @@
 :brokerPort: 9092
 
 = Discovery
+:description: Reference for the discovery ConfigMap the Stackable operator for Apache Kafka publishes, with the connection string other tools use to reach the brokers.
 :page-aliases: discovery.adoc
 
 The Stackable Operator for Apache Kafka publishes a xref:concepts:service_discovery.adoc[service discovery ConfigMap] which exposes a client configuration bundle that allows access to the Apache Kafka cluster.

docs/modules/kafka/pages/reference/environment-variables.adoc

@@ -1,4 +1,5 @@
 = Environment variables
+:description: Environment variables the Stackable operator for Apache Kafka accepts, with their default values and what each one controls.
 
 This operator accepts the following environment variables:
 

docs/modules/kafka/pages/reference/index.adoc

@@ -1,4 +1,5 @@
 = Reference
+:description: Reference for the Stackable operator for Apache Kafka, covering CRD fields, discovery ConfigMap properties, command-line parameters and environment variables.
 
 Consult the reference documentation section to find exhaustive information on:
 

docs/modules/kafka/pages/usage-guide/index.adoc

@@ -1,2 +1,3 @@
 = Usage guide
+:description: Guides for Apache Kafka on Kubernetes, covering KRaft controllers, service exposition, security, storage, logging, monitoring and overrides.
 :page-aliases: usage.adoc

docs/modules/kafka/pages/usage-guide/listenerclass.adoc

@@ -1,4 +1,5 @@
 = Service exposition with ListenerClasses
+:description: Exposing Apache Kafka brokers with ListenerClasses, covering the bootstrap and per-broker Listeners the operator creates for client connections.
 
 The operator deploys a bootstrap xref:listener-operator:listener.adoc[Listener] for each broker rolegroup, as well as a xref:listener-operator:listener.adoc[Listener] for each broker pod.
 

docs/modules/kafka/pages/usage-guide/operations/cluster-operations.adoc

@@ -1,5 +1,6 @@
 
 = Cluster operation
+:description: Cluster operations for Apache Kafka, covering how to pause reconciliation of a cluster or stop it entirely through its custom resource.
 
 The managed Kafka instances can be configured with different cluster operations like pausing reconciliation or stopping the cluster. See xref:concepts:operations/cluster_operations.adoc[cluster operations] for more details.
 

docs/modules/kafka/pages/usage-guide/operations/graceful-shutdown.adoc

@@ -1,4 +1,5 @@
 = Graceful shutdown
+:description: Graceful shutdown of Apache Kafka brokers, covering the shutdown timeout and how brokers hand over partition leadership before stopping.
 
 You can configure the graceful shutdown as described in xref:concepts:operations/graceful_shutdown.adoc[].
 

docs/modules/kafka/pages/usage-guide/operations/index.adoc

@@ -1,4 +1,5 @@
 = Operations
+:description: Operating Apache Kafka with the Stackable operator, covering graceful shutdown, Pod disruptions, Pod placement, cluster IDs and cluster operations.
 
 This section of the documentation is intended for the operations teams that maintain a Stackable Data Platform installation.