fix: style math blocks appropriately

[lars-reimann]

Closes #131.

Summary of Changes

Previously only inline math formulae where rendered properly. This was now extended to block formulae as well.

Screenshots (if necessary)

The comparison was made for sklearn / sklearn.metrics._classification / cohen_kappa_score.

Before

After

Testing instructions

Ensure block formulae are rendered as expected (as long as the LaTeX in the documentation of scikit-learn is correct):

1. Search for .. math:: in the JSON to find such cases.
2. Compare with the scikit-learn documentation, e.g. for sklearn.metrics.cohen_kappa_score.

[paul0314]

Wie in diesem Beispiel zu sehen (sklearn/sklearn._loss.glm_distribution/ExponentialDispersionModel) werden math blocks durch die Regex noch nicht vollständig richtig vorverarbeitet.