more transcode settings
this release adds more env variables to change your transcode settings
TRANSCODE_SECONDS_BUFFER -> how many second to buffer when encoding
TRANSCODE_BANDWITH_kbps -> limit how much bandwith should the transcode use
this also changes the default mp3 bitrate to 128k instead of 160k
to update follow this guide
https://github.com/madiele/TwitchToPodcastRSS#when-you-want-to-update