Lighting Window preview mode should let you reset bounding box position

[JustinPrivitera]

https://visit-sphinx-github-user-manual.readthedocs.io/en/develop/using_visit/MakingItPretty/Lighting.html#lighting-window

If you have moved the box too much in preview mode, it can be very hard to get it back to a position that makes sense. If we had a reset position button that would be helpful.

[BradWhitlock]

It's not intuitive but a middle mouse click will reset the lighting window view in preview mode.

[JustinPrivitera]

Thanks! You're right, that's not intuitive. We should add a note that mentions this to the window or add a button that does this.