Revert "Revert "added sample data""

This reverts commit 99311cd0dfd9a50eedac48b7a1f1dc6046729336.
Revert "added 3rd party peakdet.m"

This reverts commit d152b7e0108ab9ea3549ff61f9195eefd4b76a77.
Added peakdet.m 3rd party script

Public domain script. See http://www.billauer.co.il/peakdet.html