Update WHATSNEW

docs/WHATSNEW

@@ -24,6 +24,9 @@ CHANGES TO REMIND
 - NEW FEATURE: remind: The $AddBlankLines system variable controls whether or
   not a blank line is added after each reminder.
 
+- NEW FEATURE: remind: The built-in functions columns() and rows() return the
+  width and height of the terminal (in character positions) respectively.
+
 - NEW FEATURE: remind: You can add custom substitution sequences of the form
   %{name} or %*{name} that end up calling the function subst_name and using
   its return value as the replacement for the substitution sequence.