Add: normalize script to normalize volume of sounds library

sounds/normalize

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+echo "Processing file $1";
+DIR="$(dirname "$1" | awk '{ print substr ($0, 13)}')"/;
+if [ $DIR = "/" ]
+then
+        DIR=""
+fi
+mkdir -p ./normalized/$DIR
+ffmpeg-normalize "$1" \
+        -ar 48000 \
+        -c:a libopus \
+        -ofmt opus \
+        -o "normalized/$DIR$(basename "$1")"