Fix nix build

Also implement an "export chart info to csv" feature

scripts/export-chart-info.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+if [ "$#" != 2 ]; then
+    echo "Usage: $0 <from> <to>"
+    exit 1
+fi
+
+from=$1
+to=$2
+
+echo "Creating destination..."
+rm -rf "$to"
+mkdir -p "$to"
+
+echo "Exporting info..."
+sqlite3 "$from" ".header on" ".mode csv" "select * from songs" \
+  >  $to/songs.csv
+sqlite3 "$from" ".header on" ".mode csv" "select * from charts" \
+  > $to/charts.csv
+
+echo "All done :3"