NEWS: add what's new in LyX 2.3

NEWS

@@ -1,3 +1,40 @@
+What's new in version 2.3.0?
+----------------------------
+
+The new features in LyX 2.3 are detailed in
+http://wiki.lyx.org/LyX/NewInLyX23
+
+* Biblatex support
+* Multiple bibliographies
+* Inverted branches
+* Quotation marks enhancements
+* Updates to reference handling
+* Improved LaTeX handling in dialogs
+* Fonts
+* New supported languages
+* New supported LaTeX commands
+* Improvements to on-screen display of math equations
+* Automatic detection of file changes
+* Citation & reference dialogs
+* Improvements to cursor movement and selection
+* Improvements to row breaking and alignment
+* Outliner and navigation menu
+* Forward/Reverse search and error reporting
+* Change tracking
+* Code preview & highlighting
+* Shortcuts
+* New or changed LFUNs
+* Layout enhancements
+* Module enhancements
+* External templates reorganization
+* New preferences settings
+* New converters
+* Miscellaneous
+* Under the hood
+* Backported
+* Categories
+
+
 What's new in version 2.2.2?
 ----------------------------