Wrong documentation reference - many_to_many is really m2m_fields

[michaeljaszczuk]

Describe the bug
In docs page https://django-simple-history.readthedocs.io/en/3.2.0/historical_model.html#tracking-many-to-many-relationships
there is example with many_to_many argument, however in the 3.2.0 version, it's called m2m_fields

Expected behavior
Update documentation and use m2m_fields as arg name

Screenshots

[legau]

Resolved in #1042

[ddabble]

Closing, as it was resolved in the PR mentioned by @legau