I like your license choice. Is there a reason you chose Unlicense over CC0? I've never heard of it before. The text is a bit shorter than CC0 which is nice. Creative Commons recommends against using CC licenses for software so as not to step on the toes of the GPL which doesn't seem applicable if you really want public domain. [1]
Oof. I don't remember exactly, but I do remember spending a lot of time (too much time) deciding between various license options. I think in the end I chose Unlicense primarily because it's easier to find Unlicensed projects on Github.
[1] https://creativecommons.org/2011/04/15/using-cc0-for-public-...