add documentation for |+| nudge

[lennart]

if I remember correctly, nudge will delay samples by a certain amount of time to give "human"-like feeling? If so I could add the documentation for it (along with cut) right now

[kindohm]

yes, although it could result in a very inhuman feeling when large values are used :)

This will introduce "swing": |+| nudge "[0 0.04]*4"

[lennart]

please check, it's in: http://tidal.lurk.org/functions.html#nudge