Update textbook.en.md

01.curriculum/01.physics-chemistry-biology/04.Niv4/04.electromagnetism/04.electromagnetism-in-media/03.reflexion-refraction/01.reflexion-refraction-main/textbook.en.md

@@ -1,7 +1,7 @@
 ---
 title : en construction
 published :true
-visible : false
+visible : true
 ---
 
 [en construction] (direct depuis local)