Add Bloom Filter to README

Author: Jamil

README.markdown

@@ -154,7 +154,7 @@ Most of the time using just the built-in `Array`, `Dictionary`, and `Set` types
 
 ### Sets
 
-- Bloom Filter
+- [Bloom Filter](Bloom Filter/). A constant-memory data structure that probabilistically tests whether an element is in a set.
 - [Hash Set](Hash Set/). A set implemented using a hash table.
 - Multiset
 - Ordered Set