updating DIRECTORY.md

Author: shivamkb17

DIRECTORY.md

@@ -138,6 +138,7 @@
   * [Intensity Based Segmentation](computer_vision/intensity_based_segmentation.py)
   * [Mean Threshold](computer_vision/mean_threshold.py)
   * [Mosaic Augmentation](computer_vision/mosaic_augmentation.py)
+  * [Motion Detection](computer_vision/motion_detection.py)
   * [Pooling Functions](computer_vision/pooling_functions.py)
 
 ## Conversions
@@ -195,6 +196,7 @@
     * [Permutations](data_structures/arrays/permutations.py)
     * [Prefix Sum](data_structures/arrays/prefix_sum.py)
     * [Product Sum](data_structures/arrays/product_sum.py)
+    * [Rotate Array](data_structures/arrays/rotate_array.py)
     * [Sparse Table](data_structures/arrays/sparse_table.py)
     * [Sudoku Solver](data_structures/arrays/sudoku_solver.py)
   * Binary Tree