Add scan schedule to navidrome options

pages/02.linux/navidrome/default.en.md

@@ -14,6 +14,7 @@ podman run \
     -v /path/to/music:/music:ro \
     -v /path/to/data:/data \
     -e ND_ENABLETRANSCODINGCONFIG=true \
+    -e ND_SCANSCHEDULE=1h \
     -e ND_COVERJPEGQUALITY=90 \
     -e ND_DEFAULTTHEME="Electric Purple" \
     -d docker.io/deluan/navidrome:latest