add news bullet.

Author: lorenzwalthert

NEWS.md

@@ -27,7 +27,7 @@
 - empty lines are now removed between pipes (#645).
 - overhaul pgkdown site: Add search (#623), group function in Reference (#625).
 - always strip trailing spaces and make cache insensitive to it (#626).
-- typos in documentation (#643, #618, #614).
+- minor documentation improvements (#643, #618, #614, #677).
 
 # styler 1.3.2