Project velocity should rely on initial velocity until it has N weeks (the number of weeks averaged in project settings)

We've noticed that the velocity calculator abandons the initial velocity very soon, after the first non-zero point week. We think this might be a bit premature.

In our project, we've asked for velocity to be the average of the last 3 weeks. In our first week, we had a chore-only week with 0 points. After this week, velocity stayed at 10 (the initial). In our second week, we had an averagely productive week of 10 points. Although we haven't completed three weeks yet, our velocity has now shrunk to 5 points.