Convert the Tsinghua IPTV json list to m3u list.
The link to the m3u list is https://raw.githubusercontent.com/SiuKam/Tsinghua-IPTV-m3u-list/main/channels.m3u. TXT type is also available at https://raw.githubusercontent.com/SiuKam/Tsinghua-IPTV-m3u-list/main/channels.txt