Edit release notes for 2.10.0.

Author: rstam

Release Notes/Release Notes v2.10.0.md

@@ -1,20 +1,27 @@
-# .NET Driver Version 2.10.0 Placeholder Release Notes
+# .NET Driver Version 2.10.0 Release Notes
 
-The main new features in 2.10.0 are:
+The main changes in 2.10.0 are:
+
+1. A number of minor bug fixes
+2. New ReplaceOptions parameter for the ReplaceOne CRUD methods
+3. Client-side field level encryption (FLE)
 
 An online version of these release notes is available at:
 
-https://github.com/mongodb/mongo-csharp-driver/blob/master/Release%20Notes/Release%20Notes%20v2.10.0md
+https://github.com/mongodb/mongo-csharp-driver/blob/master/Release%20Notes/Release%20Notes%20v2.10.0.md
 
 The full list of JIRA issues that are currently scheduled to be resolved in this release is available at:
 
 https://jira.mongodb.org/issues/?jql=project%20%3D%20CSHARP%20AND%20fixVersion%20%3D%202.10.0%20ORDER%20BY%20key%20ASC
 
-
 Documentation on the .NET driver can be found at:
 
 http://mongodb.github.io/mongo-csharp-driver/
 
+Documentation on the new client-side field level encryption feature can be found:
+
+http://mongodb.github.io/mongo-csharp-driver/2.10/reference/driver/crud/client_side_encryption/
+
 ## Upgrading
 
 There are no known backwards breaking changes in this release.