chore(array) : readme file

Author: dhrubach

simple_array/README.md

@@ -1,22 +1,24 @@
 # problem list
 
-## easy
+## easy (10)
 
 - Advance By Offsets
+- Remove a given element from an array
 - [Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/)
 - Increment Any Arbitrary Precision Integer
 - [K-Diff Pairs in an Array](https://leetcode.com/problems/k-diff-pairs-in-an-array/)
 - Minimum Steps To End
+- Display all Prime Numbers up to n
 - [Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/)
 - [Shortest Unsorted Continuous Subarray](https://leetcode.com/problems/shortest-unsorted-continuous-subarray/)
 - [Third Maximum Number](https://leetcode.com/problems/third-maximum-number/)
 
-## medium
+## medium (3)
 
 - [kth Largest Element in an Array](https://leetcode.com/problems/kth-largest-element-in-an-array/)
 - Multiply Two Arbitrary Precision Integers
 - [Remove Duplicates from Sorted Array II](https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii/)
 
-## hard
+## hard (1)
 
 - [Best Time to Buy and Sell Stock III](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iii/)