Update the mention to the md5deep package

Update the mention to the "md5deep" package because "hashdeep" is its successor, as it can be seen on:

• https://md5deep.sf.net
• https://github.com/jessek/hashdeep/#readme
• https://packages.ubuntu.com/md5deep
• https://packages.ubuntu.com/hashdeep

Note:

    $ md5deep
    Command 'md5deep' not found, but can be installed with:
    sudo apt install hashdeep