Update RGB to hexadecimal to new bitwise version

snippets/RGB-to-hexadecimal.md

@@ -1,10 +1,22 @@
 ### RGB to hexadecimal
 
-Convert each value to a hexadecimal string, using `toString(16)`, then `padStart(2,'0')` to get a 2-digit hexadecimal value.
-Combine values using `join('')`.
+Convert given RGB parameters to hexadecimal string using bitwise left-shift operator.
 
 ```js
 const rgbToHex = (r, g, b) =>
-  [r,g,b].map( v => v.toString(16).padStart(2,'0')).join('');
-// rgbToHex(0, 127, 255) -> '007fff'
+  ((r << 16) + (g << 8) + b).toString(16).padStart(6, '0');
+// rgbToHex(255, 165, 1) -> 'ffa501'
 ```
+
+Think the RGB values as binary, the max value for each will be `255` in decimal and `11111111` (8-bit) in binary. So, the left most side in hexadecimal form is for red value, middle part is green, most right side is blue, as you probably already know. To summarize it over orange `rgb(255, 165, 1)`, `#ffa501` color.
+
+```
+                 255      165      1
+  (r << 16)   11111111 00000000 00000000
++ (g << 8)    11111111 10100101 00000000
++ (b)         11111111 10100101 00000001
+
+toString(16)     ff       a5       01
+```
+
+We simply moving values to their appropriate locations. `padStart(6, '0')` is needed for leading left most zero characters.