[File] Adding Reaper Peak files

[Martin Guy]

Hi! I just found some files here that "file" says are data but which has 
an easily-recognizable set of four-character magic words at the start: 
Reaper Peaks files containing analysis data for audio files created by a 
commercial audio workstation program.


The format is documented at https://www.reaper.fm/sdk/reapeaks.txt

and the first four bytes are (quote):


"RPKM" (v1.0) or "RPKN" (v1.1) magic header
         v1.2, REAPER 5.15+: "RPKL" for large-range peaks (used for FP media)


Thanks!

    M