Added comment about line 3

Author: Jestavo1

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
+
+// Line 3 is updating the value of the variable `count`. The `=` operator is an assignment operator, which means it takes the value on the right side (in this case, `count + 1`) and assigns it to the variable on the left side (`count`). So, it takes the current value of `count`, adds 1 to it, and then stores that new value back into `count`.