feat: add simple cli

[mvayngrib]

see my exact use case below :)

youtubemp3() {
  local video="$1"
  local title=$(ytdl -j "$video" | jq -r .title | sanitize-filename) # <<<<<<<<< YES!
  local output="$HOME/Downloads/$title.mp3"
  ytdl --filter audioonly "$video" | ffmpeg -i pipe:0 -b:a 192K -vn "$output"
}