Enhance code readability with explanatory comments

Added comments to explain the purpose of each step in the code.

Author: cywong-dev

Sprint-1/3-mandatory-interpret/3-to-pounds.js

@@ -25,3 +25,8 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+// [ChunYanWong] line 3 is used to remove the character "p" or the unit penny
+// [ChunYanWong] line 8 is used to add three 0 in front of the variable penceStringWithoutTrailingP
+// [ChunYanWong] line 9 is used to get the nearest pound from the variable above
+// [ChunYanWong] line 14 is used to get the remaining penny after converting to the nearest pound
+// [ChunYanWong] line 18 is used to display the result in pound and penny respectively