1. Change default ensure_vertical_shell_thickness value back to ensure_all as suggested by @igiannakas
2. Change default sparse_infill_pattern vaule to ipCrossHatch
* Add Ender-3 Pro cover
* Add Ender-3 Pro
* Add Ender-3 Pro .2, .4, .6, and .8
* Add Ender-3 Pro processes
* Delete Ender-3 Pro_cover.png
* Add a smaller version of Ender-3 Pro_cover.png
* Delete Ender-3 Pro_cover
* Further image improvements