RetroSpy Update Database for the MiSTer Downloader

Database to keep RetroSpy for MiSTer up to date.

Add the following in your download.ini at the root of your MiSTer's SD card.

[retrospy/retrospy-MiSTer]
db_url = https://raw.githubusercontent.com/retrospy/retrospy-MiSTer/db/db.json.zip

Once added simply run update_all to bring down the most recent version of RetroSpy for MiSTer.