- adding an spdx file (it feels like we shouldn't be doing this if we aren't a binary package)
- Turns out, on reflection, we don't actually care. So I'm not doing that.
- Updated the LICENSE file.
- Minor edits in the README.
- Updated 00-about-the-game to link to the github and include the license (otherwise, if you just visited the site, you'd have no idea).