docs: review the usage page (flipped the sections)

Signed-off-by: Gabriele Bartolini <[email protected]>

Author: gbartolini

web/docs/usage.md

@@ -81,34 +81,13 @@ This configuration enables both WAL archiving and data directory backups.
 
 ## Performing a Base Backup
 
-Once WAL archiving is enabled, the cluster is ready for backups. 
+Once WAL archiving is enabled, the cluster is ready for backups. Backups can be
+created either declaratively (with YAML manifests) or imperatively (with the
+`cnpg` plugin).
 
-### Using kubectl-cnpg plugin
+### Declarative approach (YAML manifest)
 
-The quickest way to create an on-demand backup is using the kubectl-cnpg plugin:
-
-```bash
-kubectl cnpg backup -n <namespace> <cluster-name> \
-  --method=plugin \
-  --plugin-name=barman-cloud.cloudnative-pg.io
-```
-
-:::note Migration from in-tree backup
-If you're migrating from the in-tree backup system, note that the command has changed from:
-```bash
-# Old command (in-tree backup)
-kubectl cnpg backup -n <namespace> <cluster-name> --method=barmanObjectStore
-```
-to:
-```bash
-# New command (plugin backup)
-kubectl cnpg backup -n <namespace> <cluster-name> --method=plugin --plugin-name=barman-cloud.cloudnative-pg.io
-```
-:::
-
-### Using YAML manifests
-
-Alternatively, you can create a backup using a YAML manifest:
+Create a backup resource by applying a YAML manifest:
 
 ```yaml
 apiVersion: postgresql.cnpg.io/v1
@@ -123,8 +102,28 @@ spec:
     name: barman-cloud.cloudnative-pg.io
 ```
 
-:::note
-You can apply the same concept to the `ScheduledBackup` resource.
+### Imperative approach (using the `cnpg` plugin)
+
+The quickest way to trigger an on-demand backup is with the `cnpg` plugin:
+
+```bash
+kubectl cnpg backup -n <namespace> <cluster-name> \
+  --method=plugin \
+  --plugin-name=barman-cloud.cloudnative-pg.io
+```
+
+:::note Migration from in-tree backups
+If you are migrating from the in-tree backup system, note the change in syntax:
+
+```bash
+# Old command (in-tree backup)
+kubectl cnpg backup -n <namespace> <cluster-name> --method=barmanObjectStore
+
+# New command (plugin-based backup)
+kubectl cnpg backup -n <namespace> <cluster-name> \
+  --method=plugin \
+  --plugin-name=barman-cloud.cloudnative-pg.io
+```
 :::
 
 ## Restoring a Cluster