Encourage ros2dds bridge usage for ROS 2

[JEnoch]

A new Zenoh plugin dedicated for ROS 2 has been developed:
https://github.com/eclipse-zenoh/zenoh-plugin-ros2dds

We strongly advise ROS 2 users to use it, since it better integrates with ROS 2 and brings these benefits:

• Better integration of the ROS graph (all ROS topics/services/actions can be seen across bridges)
• Better support of ROS toolings (ros2 CLI, rviz2...)
• Configuration of a ROS namespace on the bridge (instead of on each ROS Node)
• Services and Action as Zenoh Queryables with more efficiency and scalability that RPC over DDS
• Even more compact discovery information between the bridges (not forwarding all ros_discovery_info messages as such)

The Zenoh plugin for DDS will eventually be deprecated for ROS 2 usage.