There are many time series packages list here
Surprisingly few contain the most basic "hello world" univariate example: predicting the (k+1)'th number in a sequence.
So here they are.
If you are interested in contributing, issues are maintained in the timemachines package including suggestions for new notebooks here. See also the contributors guide.
Typically these notebooks are the first step in a process that leads to creation and benchmarking of autonomous time-series forecasting methods.