DOC: evaluate.VelDist missing keyword argument description

[kay-ro]

Problem description:

The documentation of the VelDist evaluation class is missing the description of several keyword arguments, namely vmin, vmax, v2max. The description how the limits of the distribution for v² and |v| are being calculated is missing.

Moreover, the calculation of the upper limit of the distribution for v² and |v|is unclear.

Suggested content improvement:

• extend class call with type hints
• add missing descriptions of keyword arguments in documentation
• potentially fix the calculation for the upper limits of the distribution for v² and |v| - or document behavior thoroughly