updating DIRECTORY.md

Author: github-actions

DIRECTORY.md

@@ -161,6 +161,7 @@
   * [Binary Search](https://github.com/TheAlgorithms/Ruby/blob/master/searches/binary_search.rb)
   * [Depth First Search](https://github.com/TheAlgorithms/Ruby/blob/master/searches/depth_first_search.rb)
   * [Double Linear Search](https://github.com/TheAlgorithms/Ruby/blob/master/searches/double_linear_search.rb)
+  * [Fibonacci Search](https://github.com/TheAlgorithms/Ruby/blob/master/searches/fibonacci_search.rb)
   * [Jump Search](https://github.com/TheAlgorithms/Ruby/blob/master/searches/jump_search.rb)
   * [Linear Search](https://github.com/TheAlgorithms/Ruby/blob/master/searches/linear_search.rb)
   * [Number Of Islands](https://github.com/TheAlgorithms/Ruby/blob/master/searches/number_of_islands.rb)