fix typo (closes https://todo.sr.ht/~xavierb/teaching-cabinet-tasks/6)
treebcc9dc424c658273759c637bc944b639f3d97014
-rw-r--r-- 96 .gitignore
drwxr-xr-x - .reuse
drwxr-xr-x - LICENSES
-rw-r--r-- 1325 README.md
-rw-r--r-- 703 book.toml
drwxr-xr-x - src