[DOC]: Instructions on how to get started are confusing and not comprehensive

[evan-palmer]

Documentation Change Type

Adding new documentation to the BlueROV2 driver documentation

Documentation Location

The project README

Documentation Problem

Per #45 the current startup instructions recommend that users start with the following command:

ros2 launch blue_bringup bluerov2_heavy.launch.py

The issue with this is that the command does not launch anything (it is not designed to) and simply shows an error message when ArduPilot fails to establish a connection with MAVROS (if the user does not have an active connection to a vehicle).

Suggested Change

The full documentation needs an update sigh, but one way to start out would be to update the README to describe how to launch the simulation environment:

ros2 launch blue_bringup bluerov2_heavy.launch.py use_sim:=true

Once #50 has been resolved, the original command could be preserved with RViz2 automatically starting. Nonetheless, when a user starts the system for the first time, they should see something (other than an error) happen.

[evan-palmer]

Duplicate of #31