update news

Author: cpsievert

NEWS.md

@@ -24,6 +24,7 @@
 ## BUG FIXES
 
 * `embed_notebook()` now works in *nteract* notebooks (see #768). 
+* Axis categories are no longer reordered for matrices (see #863).
 * Fix for hoverinfo displaying the heights of bars in the translation `geom_bar()` via `ggplotly()`. Fixes #557 and #662.
 * Font faces for axis titles are now translated in `ggplotly()`. Fixes #861.