Add Reverb_Belton BTDR

Created by: McColson

Add Belton BTDR-1H and BTDR-1V Digital Reverb module

http://www.belton.co.kr/inc/downfile.php?seq=17&file=pdf

I will also submitted the footprint and the model 3D.

Footprint request link https://github.com/KiCad/kicad-footprints/pull/1372

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