I really believe the term "open source" should be avoided if the project is not under an real open source licence: https://opensource.org/osd

E.g. this uses a "Creative Commons BY-NC-ND" license which contains: "NoDerivatives — If you remix, transform, or build upon the material, you may not distribute the modified material". So it restricts some rights that one would usually expect from an "open source" project, which can be confusing (https://opensource.org/faq#avoid-unapproved-licenses)

Cool project otherwise!