The "timer" example is actually "the same" for both f1 and f4. Do a
sanity sweep over the commentary, remove all vestiges that this was
cloned from a motor control example, and synchronize both examples.
Future work should extract the common portions "somewhere" but at least
make them consistent for now.
Be specifically careful with the usb examples. There is likely some
breakage to be expected, not sure I updated all the drivers to the
correct types for the respective chips.
