Add RTLSDR-Airband Docker deployment config

docker-compose.yml runs ghcr.io/rtl-airband/rtlsdr-airband:latest with
USB passthrough and recording volume mount. rtl_airband.conf monitors
3 EU CB channels (CH3, CH7, CH10) with NFM, bandwidth=8000, correction=-1,
split_on_transmission, and dated subdirectories.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker-compose.yml

@@ -0,0 +1,10 @@
+services:
+  rtlsdr-airband:
+    image: ghcr.io/rtl-airband/rtlsdr-airband:latest
+    container_name: sdr-recorder
+    restart: unless-stopped
+    devices:
+      - /dev/bus/usb:/dev/bus/usb
+    volumes:
+      - ./rtl_airband.conf:/app/rtl_airband.conf:ro
+      - /home/m/recordings:/recordings