Added Release Notes for v2.14.0-beta1 and updated What's new? (#652)

Author: JamesKovacs

Docs/reference/content/upgrading.md

@@ -13,6 +13,10 @@ title = "Upgrading"
 
 ### Backwards compatibility with driver version 2.7.0–2.13.x
 
+Driver version 2.14.0 only supports MongoDB 3.6 and later. It cannot connect to
+clusters running earlier versions of MongoDB. If you need to connect to
+an older cluster, please use driver version 2.13.x or earlier.
+
 Starting in 2.11.0, ``BsonSerializer.Serialize`` will throw an
 ``InvalidOperationException`` when attempting to serialize an array at
 the root of a BSON document. Prior versions would allow this invalid operation.

Docs/reference/content/what_is_new.md

@@ -10,10 +10,16 @@ title = "What's New"
 
 ## What's New in 2.14.0
 
-The main new features in 2.1.40 include:
+The main new features in 2.14.0-beta1 include:
 
 * A beta version of the new LINQ provider (known as LINQ3, see: [LINQ3]({{< relref "reference\driver\crud\linq3.md" >}}))
 * The current LINQ provider (known as LINQ2) continues to be available and is still the default LINQ provider for now
+* Support for Zstandard and Snappy on Linux and MacOS
+* Added connection storm avoidance features
+* Use "hello" command for monitoring if supported
+* Removed support for .NET Framework 4.5.2; minimum is now 4.7.2
+* Removed support for .NET Standard 1.5; minimum is now 2.0
+* Minimum server version is now MongoDB 3.6+
 
 ## What's New in 2.13.0
 

Release Notes/Release Notes v2.14.0-beta1.md

@@ -0,0 +1,29 @@
+# .NET Driver Version 2.14.0-beta1 Release Notes
+
+This is a beta release for the 2.14.0 version of the driver.
+
+The main new features in 2.14.0-beta1 include:
+
+* A beta version of the new LINQ provider (known as LINQ3, see: [LINQ3]({{< relref "reference\driver\crud\linq3.md" >}}))
+* The current LINQ provider (known as LINQ2) continues to be available and is still the default LINQ provider for now
+* Support for Zstandard and Snappy on Linux and MacOS
+* Added connection storm avoidance features
+* Use "hello" command for monitoring if supported
+* Removed support for .NET Framework 4.5.2; minimum is now 4.7.2
+* Removed support for .NET Standard 1.5; minimum is now 2.0
+* Minimum server version is now MongoDB 3.6+
+
+An online version of these release notes is available at:
+
+https://github.com/mongodb/mongo-csharp-driver/blob/master/Release%20Notes/Release%20Notes%20v2.14.0-beta1.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%202.14.0%20ORDER%20BY%20key%20ASC
+
+The list may change as we approach the release date.
+
+Documentation on the .NET driver can be found at:
+
+http://mongodb.github.io/mongo-csharp-driver/
+