make some cosmetic changes and double-check calculation of recall

[ausgerechnet]

• make README more readable
• fix a line in tests/data/candidate.bio
• add additional tests for unlabelled recall and precision

[minhddb]

Thanks for the cleanup!

The cosmetic updates improve readability and consistency across the file without affecting functionality. I especially appreciate the formatting alignment and naming consistency — it makes the code easier to scan and maintain.

I’ve reviewed the changes and confirmed there’s no impact on logic or behavior. 👍

Looks good to merge from my side.