Before publishing

1. Make sure `reference.md` is up to date
  - Also the stylesheets
1. `cargo test`
  - Passes all tests
  - Check if `character_test.html`, `icon_test.html`, `math_test.html` and `reference.html` are rendered properly
1. `cargo test --release`
  - Passes all tests
  - Check if `character_test.html`, `icon_test.html`, `math_test.html` and `reference.html` are rendered properly