update: Clarify age variable reassignment and correct declaration to 'let' in sprint -1 of 1.js

Author: SuWebOnes

Sprint-1/2-mandatory-errors/1.js

@@ -2,3 +2,6 @@
 
 const age = 33;
 age = age + 1;
+console.log(age); // Output: 34
+// The code above declares a variable age with an initial value of 33.
+// It then reassigns the value of age by adding 1 to its current value, so the declaration must be using 'let' keyword.