Initial release.
**Added**
- [1], [4], [12]: bootstrap cosmofy to build itself
- [2], [6], [8], [9], [13]: JSON receipt and schema
- [3], [5]: `--receipt-url`, `--release-url`, `--release-version`
- [7]: `--self-update`, `--self-update --help`, `--self-update --version`
- [10]: release notes
- [11]: auto-upload build artifacts to GitHub Release