A tidycpt object has a set of changepoints returned by the
algorithm that segmented the time series.
That changepoint set was obtained using a specific model.
Treating this changepoint set as fixed, the compare_models() function
fits several common changepoint models to the time series and changepoint
set, and returns the results of glance().
Comparing the fits of various models could lead to improved understanding.
Alternatively, compare_algorithms() runs several fast changepoint detection
algorithms on the original time series, and consolidates the results.