Renamed parameter, added param desc.

Also fixed inefficiency where potential was fetched twice.
Fixed title of plot.
Added script for solving stationairy gaussian..

wavepacket in a finite potential well. Width is universal.
Removed angular momentum (reason for wavepacket going forwards) in
initial state.

Needs more work.

P.S.: Is there a problem in the units? Simulation doesn't change
correctly when dt and T are changed.
Added script using CN for gaussian wave in HO.

Started off-axis to illustrate that it gains momentum.