man: enhance the description of systemd-stdio-bridge
    
    I hope that this fixes the comment
    https://github.com/systemd/systemd/pull/22141#issuecomment-1013960371
    > As someone who doesn't know what this prog does
    
    The listing in the man page is sorted according to logical
    use: all the options setting the address are now together.
    
    (cherry picked from commit b7bb58ef70b0c876941a1c31ed4e2f5f1dc5ed0e)