Add count exercise explanation

Author: BrianY315

Sprint-2/1-key-exercises/1-count.js

@@ -4,4 +4,6 @@ count = count + 1;
 console.log(count);
 
 // Line 1 is a variable declaration, creating the count variable with an initial value of 0
-// Describe what line 3 is doing, in particular focus on what = is doing
+// Line 3 is using the assignment operator (=) to update the value of count.
+// It reads the current value of count, adds 1 to it, and then stores the result back into count.
+// So the value changes from 0 to 1.