sed -En '
1{s/^.*$/OS:/; p}

/^submenu .Advanced options for /,/^}/d

# WinOS
/^menuentry .*Windows/{
s/^menuentry /\n - Name: /
s/ --(class|id) .*$/\n   Type: WinOS/
p
}

# LinOS
/^menuentry /{
s/^menuentry /\n - Name: /
s/ --(class|id) .*$/\n   Type: LinOS/
p
}

# Root
/set root=/{
s/^\s*set root=/   Root: /
p
}

' "$@"