Update 12.temporary_ins/20.magnetostatics-vacuum/20.causes-stationary-magnetic-field/20.overview/cheatsheet.fr.md

Update 12.temporary_ins/10.electrostatics-vacuum/20.causes-stationary-electric-field/20.overview/cheatsheet.fr.md

Update 12.temporary_ins/95.electromagnetism-in-media/10.propagation-lhi-media/10.main/textbook.fr.md