Mention Eclipse Trace Compass plugin for ROS 2 in README

[christophebedard]

It was brought to my attention that the Eclipse Trace Compass (Incubator) plugin for ROS 2 is never directly mentioned in the README here. It's indirectly mentioned through other things mentioned in the README, such as the message flow paper and the ROSCon 2023 talk, but not directly. It's also not mentioned in the tutorial in the ROS 2 docs, but that one is more intentional, since the goals is more about illustrating what can be done with the trace data. Nevertheless, it could be mentioned there too.

What prevents me -- and probably what prevented me in the past -- from adding a direct mention of the Trace Compass plugin is that it's not really documented. Trace Compass itself is documented (although the docs are kind of daunting), but the ROS 2 plugin is not. I'm specifically talking about describing what information the views show, how it works, etc. It's explained in the message flow paper (including in a related repository here), but that shouldn't be used as documentation!

It's unclear where this documentation should live. There is a documentation page for the ROS 2 plugin in the Trace Compass Incubator docs, but it just points to the repo for the message flow paper (which, to be fair, does have some OK-ish instructions, but no pictures or anything): https://archive.eclipse.org/tracecompass.incubator/doc/org.eclipse.tracecompass.incubator.ros2.doc.user/User-Guide.html. An alternative could be to create another tutorial in the ROS 2 docs (which the TC Incubator plugin page could link to), but it makes a bit more sense to put it closer to where the actual code is, i.e., in Trace Compass.

Therefore, I plan to properly document it in the documentation for the Trace Compass Incubator ROS 2 plugin and then link to it in the README here, and potentially in the tutorial in the ROS 2 docs.