Add only download Auto Playlist

[Interstellar-pi]

Please tick all applicable boxes.

• [X] I am using Python 3.5 or higher (run python --version on the command line)
• [X] I have followed the official guides to install the bot for my system
• [X] I have updated my dependencies to the latest version using the appropriate update script

Which version are you using?

• [X] The latest master version (1.9.8)
• [ ] The latest review version

What type of issue are you creating?

• [ ] Bug
• [X] Feature request
• [ ] Question

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Could you add a option to download auto playlist songs only.