MOTOR-974 Document Queryable Encryption API as "Public Technical Preview" (#182)

Author: blink1073

doc/changelog.rst

@@ -3,6 +3,23 @@ Changelog
 
 .. currentmodule:: motor.motor_tornado
 
+Motor 3.1
+---------
+
+Motor 3.1 adds support for the Queryable Encryption beta with MongoDB 6.0.
+Note that backwards-breaking changes may be made before the final release.
+
+The new Queryable Encryption changes that are in beta are:
+
+- The `encrypted_fields` argument to the
+  :class:`~motor.motor_tornado.MotorCollection` constructor, and the
+  :meth:`~motor.motor_tornado.MotorDatabase.create_collection`
+  and :meth:`~motor.motor_tornado.MotorDatabase.drop_collection` methods.
+- The `query_type` and `contention_factor` arguments to
+  :meth:`motor.motor_asyncio.AsyncIOMotorClientEncryption.encrypt` and
+  :meth:`motor.motor_tornado.MotorClientEncryption.encrypt`.
+
+
 Motor 3.0
 ---------