Hawkeye is a real-time 3D flight visualizer (not a simulator) that
replaces jMAVSim's display-only mode for SIH. Adds a dedicated Hawkeye
docs page covering installation, SIH SITL usage, multi-vehicle support,
and ULog replay. Updates the SIH page to recommend Hawkeye instead of
jMAVSim for visualization.
Signed-off-by: Ramon Roche <mrpollo@gmail.com>
