DOCS-671 min-max FAQ landing page

Author: kay-kim

source/faq/indexes.txt

@@ -116,3 +116,14 @@ The :operator:`$ne` and :operator:`$nin` operators are not selective.
 See :ref:`index-selectivity`. If you need to use these,
 it is often best to make sure that an additional, more selective
 criterion is part of the query.
+
+.. _faq-index-min-max:
+
+Can I use index keys to constrain query matches?
+------------------------------------------------
+
+The :method:`min() <cursor.min()>` and the :method:`max()
+<cursor.max()>` methods provide a way to constrain the results of the
+:method:`find() <db.collection.find()>` method using index keys.
+
+