Add release notes for DTR 2.3

datacenter/dtr/2.3/guides/release-notes.md

@@ -9,3 +9,50 @@ known issues for each DTR version.
 
 You can then use [the upgrade instructions](../admin/upgrade.md),
 to upgrade your installation to the latest release.
+
+## DTR 2.3.0 beta 1
+
+(17 July 2017)
+
+### New Features
+
+* Repositories can now be configured to be “immutable” in that any existing
+image can not be overwritten or deleted.
+* You can now define promotion policies, to automatically copy images from one
+repository to another.
+* DTR now has UX for easily creating webhooks for events in repositories such
+as image pushes, scans, deletions, and promotions.
+* Added support for scanning Windows images for vulnerabilities.
+* Support was added for handling manifest-lists for multi-architecture images.
+This allows pulling different images with the same tag such as Linux and Windows.
+* You can now use the web UI in Chinese.
+
+##  General Improvements
+
+### UI/UX
+
+* The users page is now paginated to decrease long load times.
+* Fixed the login page to be more resilient to improperly configured domain names.
+
+### docker/dtr
+
+* Removed requiring the `--dtr-external-url` flag during DTR installation.
+* Improved error handling.
+* Added extended help to the installer with the `--help-extended` flag.
+
+### Storage
+* Preserve the NFS hostname instead of resolving it during DTR installation.
+* Allow using S3 compatible storage with customized certificates or without TLS
+verification.
+
+### Misc
+
+* Simplified content cache configuration.
+* Removed old, insecure 3des from the cipher list.
+* Allow refresh tokens with basic auth when using the DTR API.
+* Added the ability to automatically rescan any previously scanned image.
+
+## Known issues
+
+* The web UI works best with Chrome and Firefox. Full support for
+Internet Explorer will be added on the GA release