RFC use JSON files from downloads.openwrt.org

[aparcar]

Hi, cool project!

After being tied to have ASU parse the download server, I started to add some hidden JSON files for initial testing. Maybe you could incorporate them in your tool to make things easier?

• Latest versions: https://downloads.openwrt.org/.versions.json
• Available targets: https://downloads.openwrt.org/releases/23.05.3/.targets.json
• Available packages: https://downloads.openwrt.org/releases/23.05.3/packages/aarch64_cortex-a53/.index.json

If these files happen to be of use, I may make them visible to everyone (i.e. removing the leading dot).

[efahl]

Dup of #2