Repository: Git rewrite / force push

On today (September 2nd, 2023) there was a forced rewrite by me to the repository to remove `exported.csv` , a 21kB export of UNIHAN data (generated by `unihan-etl`, this very app). It was accidentally added to the repo.

The tool used: https://github.com/newren/git-filter-repo/

Command:

```console
git filter-repo --invert-paths --path exported.csv --force
```