Minor code style improvements

Tabs are corrected, semantic blocks are separated.

Searches/binary_search.rb

@@ -13,13 +13,16 @@ else
       front = middle + 1
     end
   end
+  
   nil
 end
 
 puts "Enter a sorted space-separated list:"
 arr = gets.chomp.split(' ').map(&:to_i)
+
 puts "Enter the value to be searched:"
 value = gets.chomp.to_i
+
 puts if binary_search(arr, value) != nil
   "Found at index #{binary_search(arr, value)}"
 else