feat: add num_decimals config

[kod-kristoff]

Fixes #6

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.0%. Comparing base (7ba1114) to head (e93df9e).

Additional details and impacted files

Files	Coverage Δ
...ent/src/sbx_sentence_sentiment_kb_sent/__init__.py	100.0% <100.0%> (ø)
.../src/sbx_sentence_sentiment_kb_sent/annotations.py	100.0% <100.0%> (ø)
...x_sentence_sentiment_kb_sent/sentiment_analyzer.py	100.0% <100.0%> (ø)