docs: OSPC-367 improve operator restore info (#565)

* docs: OSPC-367 Expand on operator restore opts

The operator supports restoring a single database. That is a useful
feature worth noting in our own docs for those preferring to use the
operator versus manually dumping and restoring.

* docs: OSPC-367 Demo checking restore status

* docs: OSPC-367 Move operator tips toward the top

docs/infrastructure-mariadb-ops.md

@@ -87,9 +87,40 @@ dump to your MariaDB database.
 Refer to the mariadb-operator [restore documentation](https://github.com/mariadb-operator/mariadb-operator/blob/main/docs/BACKUP.md#restore)
 for more information.
 
+!!! tip "Operator Restore Tips"
+
+    1. If you have multiple backups available, the operator is able to infer
+    which backup to restore based on the `spec.targetRecoveryTime` field
+    discussed in the operator documentation [here](https://github.com/mariadb-operator/mariadb-operator/blob/main/docs/BACKUP.md#target-recovery-time).
+    2. The referred database (db1 in the example below) must previously exist
+    for the Restore to succeed.
+    3. The mariadb CLI invoked by the operator under the hood only supports
+    selecting a single database to restore via the `--one-database` option,
+    restoration of multiple specific databases is not supported.
+
+### Restore All Databases
+
+!!! danger "The following command may lead to data loss"
+
+    ``` shell
+    cat <<EOF | kubectl -n openstack apply -f -
+    apiVersion: k8s.mariadb.com/v1alpha1
+    kind: Restore
+    metadata:
+      name: maria-restore
+    spec:
+      mariaDbRef:
+        name: mariadb-cluster
+      backupRef:
+        name: mariadb-backup
+    EOF
+    ```
+
+### Restore Single Database
+
 !!! danger "The following command may lead to data loss"
 
-    ```shell
+    ``` shell
     cat <<EOF | kubectl -n openstack apply -f -
     apiVersion: k8s.mariadb.com/v1alpha1
     kind: Restore
@@ -100,11 +131,19 @@ for more information.
         name: mariadb-cluster
       backupRef:
         name: mariadb-backup
+      databases: db1
     EOF
     ```
 
-!!! tip
+### Check Restore Progress
+
+!!! success "Simply _get_ the restore object previously created"
+
+    ``` shell
+    kubectl -n openstack get restore maria-restore
+    ```
 
-    If you have multiple backups available, the operator is able to infer which
-    backup to restore based on the `spec.targetRecoveryTime` field discussed
-    in the operator documentation [here](https://github.com/mariadb-operator/mariadb-operator/blob/main/docs/BACKUP.md#target-recovery-time).
+    ``` { .no-copy }
+    NAME            COMPLETE   STATUS    MARIADB           AGE
+    maria-restore   True       Success   mariadb-cluster   26s
+    ```