Code documentation

[sfm-user-1]

Hi, thanks for your work and for sharing the code. I noticed that some of the docstrings don't agree with the function signatures, e.g. an extra df argument

https://github.com/RuojinCai/doppelgangers/blob/43d9eb06f89d882a288644983f877467b741c2f9/doppelgangers/utils/dataset.py#L47

or missing docstrings, e.g. https://github.com/RuojinCai/doppelgangers/blob/main/doppelgangers/utils/loftr_matches.py#L31

Would it be possible to upgrade the code quality, by adding type annotations and docstrings to each function, by formatting the code with a code formatter such as python black, and using a style guide such as Google style guide? (https://google.github.io/styleguide/pyguide.html)