Add comments for code explanation in 3-to-pounds.js

Added comments to explain the purpose of the code.

Author: Motorcycle-lab

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

@@ -23,3 +23,5 @@ console.log(`£${pounds}.${pence}`);
 // You need to do a step-by-step breakdown of each line in this program
 // Try and describe the purpose / rationale behind each step
 
+// To begin, we can start with
+// 1. const penceString = "399p": initialises a string variable with the value "399p"