Update runtime files.
diff --git a/runtime/doc/windows.txt b/runtime/doc/windows.txt
index 8e8b0bb..be26841 100644
--- a/runtime/doc/windows.txt
+++ b/runtime/doc/windows.txt
@@ -1,4 +1,4 @@
-*windows.txt*   For Vim version 8.0.  Last change: 2017 Aug 21
+*windows.txt*   For Vim version 8.0.  Last change: 2017 Sep 08
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -1034,6 +1034,7 @@
 		   =	a readonly buffer
 		   R	a terminal buffer with a running job
 		   F	a terminal buffer with a finished job
+		   ?    a terminal buffer without a job: `:terminal NONE`
 		    +	a modified buffer
 		    x   a buffer with read errors