This format generates fewer token while maintaining the quality:

```
Model                     Generated tokens ↓    DeltaChrF ↑
0306-seed-multi-regions   46,239                80.62
0304-seed-no-edits        110,871               80.61
0303-seed                 271,457               79.62
```

In addition to the student format, this change adds a new teacher
prompt. It seems to be worse than the original, but I haven't optimized
it at all. Keeping it for now as a base for potential improvements.


Release Notes:

- N/A