Dynsec doc tweaks.

www/pages/documentation/dynamic-security.md

@@ -25,7 +25,7 @@ installations, but will not be activated by default.
 ## Concepts
 
 This section describes the concepts of how the plugin operates. If you want to
-find out how to use the plugin features, look in the [Usage] section below.
+find out how to use the plugin features, look in the [Installation] section below.
 
 The plugin allows you to create three main objects, `clients`, `groups`, and `roles`.
 
@@ -280,7 +280,7 @@ If allowed, anything connecting without a username will be assigned to a group
 that you define. By assigning roles to that group, you can control what
 anonymous devices can access.
 
-## Initial configuration
+## Installation
 
 To use the Dynamic Security plugin, it must be configured in the broker and an
 initial plugin configuration must be generated.
@@ -303,7 +303,9 @@ It is recommended to use `per_listener_settings false` with this plugin, so all
 listeners use the same authentication and access control.
 
 The `dynamic-security.json` file is where the plugin configuration will be
-stored. To generate an initial file, use the `mosquitto_ctrl` utility.
+stored. This file will be updated each time you make client/group/role changes,
+during normal operation the configuration stays in memory. To generate an
+initial file, use the `mosquitto_ctrl` utility.
 
 ```
 mosquitto_ctrl dynsec init path/to/dynamic-security.json admin-user
@@ -338,7 +340,18 @@ the `#` hierarchy by default. You are strongly encouraged to keep the admin
 user purely for administering the plugin, and create other clients for your
 application.
 
-## Using mosquitto_ctrl with a running broker
+## Usage
+
+All control of the plugin after initial installation is through the MQTT topic
+API at `$CONTROL/dynamic-security/v1`. This allows integrations to be built,
+but isn't the best choice for people to use directly. The `mosquitto_ctrl`
+command provided with Mosquitto implements support for the dynamic security
+plugin API, as described below. Other options include the [Management Center
+for Mosquitto](https://docs.cedalo.com/latest/) which is an open source web
+based tool for controlling the plugin and other features. The Management Center
+is not part of the Mosquitto project.
+
+### Using mosquitto_ctrl with a running broker
 
 The initial configuration is the only time that `mosquitto_ctrl` does not
 connect to a broker to carry out the configuration. All other commands require