Update...

Update 12.temporary_ins/90.electromagnetism-in-vacuum/20.electromagnetic-waves-vacuum/20.overview/cheatsheet.fr.md

12.temporary_ins/90.electromagnetism-in-vacuum/20.electromagnetic-waves-vacuum/20.overview/cheatsheet.fr.md

@@ -9,7 +9,7 @@ lessons:
        name: LINÉAIRE-4 : Propagation des ondes EM dans le vide
        order: 1
     - 
-       slug: electromagnetic-waves-propagation-from-vacuum-to-isotropic-media
+       slug: electromagnetic-waves-propagation-from-vacuum-to-isotropic-media-fr
        name: PARALLÈLE-4 : Propagation des ondes EM, du vide aux milieux matériels isotropes
        order: 2
     -