updated count.js file with my reasoing

Author: Mugs3

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

@@ -4,3 +4,5 @@ count = count + 1;
 
 // 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
+
+//Answer: The = means assignment. The value of count is 0 but it increments by 1