Test against other packages, e.g. python-titlecase

[alerque]

Among alternative implementations in other languages there are some test suites with nice collections of hard cases. At least for English. I haven't run across any for Turkish, but it would be nice to compare our output for certain style guides with other libraries.

Here is one for English / Gruber style: https://github.com/ppannuto/python-titlecase/blob/main/titlecase/tests.py

[alerque]

Or perhaps upstream these test cases to the crate where the style is actually implemented.