Add LICENSE

[sdruskat]

This repository should be properly licensed.

I suggest to follow the REUSE Specs, and

• Create a LICENSES folder with text files for CC BY-4.0 Intl. (for content), CC0 for unimportant files.
• Add a text snippet to the README (see below)
• Add license (at least MIT) for the Minimal Mistakes template

# Licenses

Unless otherwise noted, all content on the website is licensed under [CC BY-4.0 Intl.](link to license file).
All configuration, templating, Markdown and other files are licensed under [CC0](link to license file).
This website uses the [Minimal Mistakes](link to MM GitHub page) template, which is licensed under an [MIT license](link to license file).

[knarrff]

The licenses are fine with me. I'd like to point out that strictly following REUSE can be a considerable effort (requires for all files either header tags or a second file with that meta-information (or a global dep5-file)).