updating DIRECTORY.md

Author: github-actions

DIRECTORY.md

@@ -22,6 +22,7 @@
  * [DecimalToHex](https://github.com/TheAlgorithms/Javascript/blob/master/Conversions/DecimalToHex.js)
  * [DecimalToOctal](https://github.com/TheAlgorithms/Javascript/blob/master/Conversions/DecimalToOctal.js)
  * [HexToRGB](https://github.com/TheAlgorithms/Javascript/blob/master/Conversions/HexToRGB.js)
+ * [RGBToHex](https://github.com/TheAlgorithms/Javascript/blob/master/Conversions/RGBToHex.js)
  * [RomanToDecimal](https://github.com/TheAlgorithms/Javascript/blob/master/Conversions/RomanToDecimal.js)
 
 ## Data-Structures