Update cheatsheet.en.md

12.temporary_ins/90.electromagnetism-in-vacuum/10.maxwell-equations/20.overview/cheatsheet.en.md

@@ -874,10 +874,14 @@ I recognize here the law of conservation of charge.
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   $`\Longrightarrow`$ Light is only a tiny part of electromagnetic waves.   
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-  $`\Longrightarrow`$ A *whole new world of "lights"* is revealed, called the **electromagnetic spectrum**.   
+  $`\Longrightarrow`$ A *whole new world of "lights"* is revealed, called the **electromagnetic spectrum**.  
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+<br>
 
 ![Electromagnetic Spectrum](astro-electromagnetic-spectrum-N4_1_fr_L1200.jpg)
 
+<br>
+
 * In particular, **knowledge of the universe** resulted *before Maxwell* from the sole observation of the *visible domain*,   
 
 ![Visible Sky](ciel-visible-bsp_L1200.jpg)