updating DIRECTORY.md

Author: github-actions

DIRECTORY.md

@@ -223,5 +223,7 @@
   * [Sort Tests](https://github.com/TheAlgorithms/Ruby/blob/master/sorting/sort_tests.rb)
 
 ## Strings
+  * [Boyer Moore Horspool Search](https://github.com/TheAlgorithms/Ruby/blob/master/strings/boyer_moore_horspool_search.rb)
+  * [Boyer Moore Horspool Search Test](https://github.com/TheAlgorithms/Ruby/blob/master/strings/boyer_moore_horspool_search_test.rb)
   * [Max K Most Frequent Words](https://github.com/TheAlgorithms/Ruby/blob/master/strings/max_k_most_frequent_words.rb)
   * [Max K Most Frequent Words Test](https://github.com/TheAlgorithms/Ruby/blob/master/strings/max_k_most_frequent_words_test.rb)