Update Readme.md

Author: pandeyxamit

sortingAlgo/bubbleSort/Readme.md

@@ -13,11 +13,11 @@ if they are not in the intended order. The order can be ascending or descending.
 ## Complexity
 Bubble Sort is one of the simplest sorting algorithms. Two loops are implemented in the algorithm.
 ### Time Complexities:
-* #### Worst Case Complexity: O($n^2$)
+* #### Worst Case Complexity: O(n<sup>2</sup>)
 	If we want to sort in ascending order and the array is in descending order then, the worst case occurs.
 * #### Best Case Complexities: O(n)
 	If the array is already sorted, then there is no need for sorting.
-* #### Average Case Complexity: O($n^2$)
+* #### Average Case Complexity: O(n<sup>2</sup>)
 	It occurs when the elements of the array are in jumbled order (neither ascending nor descending).
 
 ### Space Complexity: