Per https://github.com/exercism/docs/blob/ccdf58f97f698c265f0f67fa7cb9d94084d7f0a3/language-tracks/exercises/README.md#files
See https://github.com/exercism/docs/blob/fe38450da526a35368e98fdb2f83ca40f1298aee/contributing-to-language-tracks/README.md#adding-hints