docs: uxrce_dds rate_limit option

Author: GuillaumeLaine

docs/en/middleware/uxrce_dds.md

@@ -428,9 +428,11 @@ publications:
 
   - topic: /fmu/out/vehicle_odometry
     type: px4_msgs::msg::VehicleOdometry
+    rate_limit: 150.
 
   - topic: /fmu/out/vehicle_status
     type: px4_msgs::msg::VehicleStatus
+    rate_limit: 50.
 
   - topic: /fmu/out/vehicle_trajectory_waypoint_desired
     type: px4_msgs::msg::VehicleTrajectoryWaypoint
@@ -465,6 +467,8 @@ Each (`topic`,`type`) pairs defines:
    - `/fmu/out/` for topics that are _published_ by PX4.
    - `/fmu/in/` for topics that are _subscribed_ by PX4.
 4. The message type (`VehicleOdometry`, `VehicleStatus`, `OffboardControlMode`, etc.) and the ROS 2 package (`px4_msgs`) that is expected to provide the message definition.
+5. **(Optional)**: An additional `rate_limit` field (only for publication entries), which specifies the maximum rate (Hz) at which messages will be published on this topic by PX4 to ROS 2.
+   If left unspecified, the maximum publication rate limit is set to 100 Hz.
 
 `subscriptions` and `subscriptions_multi` allow us to choose the uORB topic instance that ROS 2 topics are routed to: either a shared instance that may also be getting updates from internal PX4 uORB publishers, or a separate instance that is reserved for ROS2 publications, respectively.
 Without this mechanism all ROS 2 messages would be routed to the _same_ uORB topic instance (because ROS 2 does not have the concept of [multiple topic instances](../middleware/uorb.md#multi-instance)), and it would not be possible for PX4 subscribers to differentiate between streams from ROS 2 or PX4 publishers.