feat: add json output format support to storage:list

This will allow the command to be used in a programmatic fashion.

docs/advanced-usage/persistent-storage.md

@@ -6,7 +6,7 @@ The preferred method to mount external containers to a Dokku managed container,
 
 ```
 storage:ensure-directory [--chown option] <directory>  # Creates a persistent storage directory in the recommended storage path
-storage:list <app>                                     # List bind mounts for app's container(s) (host:container)
+storage:list <app> [--format text|json]                # List bind mounts for app's container(s) (host:container)
 storage:mount <app> <host-dir:container-dir>           # Create a new bind mount
 storage:report [<app>] [<flag>]                        # Displays a checks report for one or more apps
 storage:unmount <app> <host-dir:container-dir>         # Remove an existing bind mount
@@ -34,6 +34,23 @@ dokku storage:list node-js-app
        /var/lib/dokku/data/storage/node-js-app:/app/storage
 ```
 
+The output format can also be set to `json` for programmatic access:
+
+
+```shell
+dokku storage:list node-js-app --format json
+```
+
+```
+[
+  {
+    "host_path": "/var/lib/dokku/data/storage/node-js-app",
+    "container_path": "/app/storage",
+    "volume_options": ""
+  }
+]
+```
+
 ### Creating storage directories
 
 > New as of 0.25.5

docs/development/plugin-triggers.md

@@ -2424,7 +2424,7 @@ DOKKU_SCHEDULER="$1"; APP="$2"; REMOVE_CONTAINERS="$3";
 
 - Description: Returns a list of storage mounts
 - Invoked by: `dokku storage:list` and `dokku deploy`
-- Arguments: `$APP`
+- Arguments: `$APP $PHASE $FORMAT`
 - Example:
 
 ```shell