Update task.md | Fix grammar

Replace the value in the middle by "Classics". changed to Replace the value in the middle with "Classics" as the word 'with' describes the situation better

Author: mukulkandhari

1-js/05-data-types/04-array/2-create-array/task.md

@@ -8,7 +8,7 @@ Let's try 5 array operations.
 
 1. Create an array `styles` with items "Jazz" and "Blues".
 2. Append "Rock-n-Roll" to the end.
-3. Replace the value in the middle by "Classics". Your code for finding the middle value should work for any arrays with odd length.
+3. Replace the value in the middle with "Classics". Your code for finding the middle value should work for any arrays with odd length.
 4. Strip off the first value of the array and show it.
 5. Prepend `Rap` and `Reggae` to the array.