Add \jump to create arbitrary JumpScripts manually
This fills a gap in manual repeat commands. Previously, only
\repeat segno
and \fine
could create JumpScripts.
\jump "markup"
is analogous to \mark "markup"
. It creates a JumpScript
with the given markup. It also triggers the same automatic bar line
selection as coda mark events and D.S. events.
Closes #5272 (closed).
Doc updates are deferred to avoid conflicting with work already in the countdown.