fix, provide a proper multiline Usage for truffle

Signed-off-by: Sebastian Freundt <freundt@fresse.org>
doc, clarify the 2 truffle modes' purposes

Signed-off-by: Sebastian Freundt <freundt@fresse.org>
Merge branch 'doc/truffle' into next

* doc/truffle:
  doc, clarify the 2 truffle modes' purposes
  fix, provide a proper multiline Usage for truffle