Is your feature request related to a problem? Please describe.

When you create a new cell (e.g., montepy.Cell()) it has importances for all particles set to 0. This is generally not the desired importance. 1.0 is a much safer and generally neutral cell importance to use.

Describe the solution you'd like

import montepy
cell = montepy.Cell()
assert cell.importance.neutron == 1.0

Describe alternatives you've considered

Keep it at 0.0. However this messed me up quite a few times as well.