added explanation for 1-count.js'

Author: Alex Jamshidi

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

@@ -4,3 +4,6 @@ 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 reassigning the variable 'count' to a new value. The new value that 'count' will take on is the existing value plus 1.
+// Given count is assigned a value of 0 in line 1, after running line 3 the value of count would be expected to be 1.