Adding rows in Power Query

I have a relativally simple question, but I can't figure out how to solve it.

I have created a simple dummy variant of my dataset. Ofcourse the real dataset is much larger, but it is basically like this:

My desired result would be to automatically add 12 rows for each row, standing for the months. So my desired result looks like this:

Case somebody help me with the M language command that I would need to achieve this?