Due to recent development of tools and discussions, this
is something that came up and has probably been overdue
for ages.
Document key concepts of how the iidx engine works regaring
rendering, game loop and (song) sync.
Add a “syncbook” that provides context and guidelines how
to configure any (modern) system to work properly with iidx.
Add some additional symptoms and reasoning as this is different
for 14 to 17 compared to any other iidx version on how to use
the PCBID you get from server operators.
