Update runtime files
diff --git a/runtime/doc/diff.txt b/runtime/doc/diff.txt
index 8c1f03a..6de4bfa 100644
--- a/runtime/doc/diff.txt
+++ b/runtime/doc/diff.txt
@@ -1,4 +1,4 @@
-*diff.txt* For Vim version 8.1. Last change: 2019 Jul 27
+*diff.txt* For Vim version 8.1. Last change: 2019 Nov 10
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -68,11 +68,12 @@
The options can still be overruled from a modeline when re-editing the file.
However, 'foldmethod' and 'wrap' won't be set from a modeline when 'diff' is
set.
+See `:diffoff` for an easy way to revert the options.
The differences shown are actually the differences in the buffer. Thus if you
make changes after loading a file, these will be included in the displayed
diffs. You might have to do ":diffupdate" now and then, not all changes are
-immediately taken into account.
+immediately taken into account, especially when using an external diff command.
In your .vimrc file you could do something special when Vim was started in
diff mode. You could use a construct like this: >