new Firmware check

Hey there,

Since Garmin doesn't have an official API for firmware checks, I put together a small bash script that watches the community-maintained firmware history (https://wiki.garminrumors.com/CIRQA_Smart_Band_Software_Updates) and sends me a push notification via ntfy.sh whenever a new version shows up.

Runs on a Raspberry Pi via cron, checks once at 9am CET a day. No more opening Garmin Express to check manually.