Missing license or usage information

[hoall]

Hello,

first, thank you for sharing your slides. They're brilliant. Unfortunatly you haven't added a license. A license would make clear, under which circumstance it is allowed to use your slides. Even more than to tell "feel free to steal".

I suggest adding a creative commons license like CC BY or CC BY SA.
More information: https://creativecommons.org/choose/

Again, thank you for your great work.