Document diff-remove-trailing-whitespace

* doc/emacs/files.texi (Diff Mode): Trailing whitespace updates.

* lisp/vc/diff-mode.el (diff-remove-trailing-whitespace): Doc fix.

* etc/NEWS: Related markup.

1 files changed, 7 insertions, 4 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 275e33d8026..5fa57ac23bd 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -392,18 +392,21 @@ details.
 
 ** Diff mode
 
+---
 *** Changes are now highlighted using the same color scheme as in
 modern VCSes.  Deletions are displayed in red (new faces
-`diff-refine-removed' and `smerge-refined-removed' and new definition
+`diff-refine-removed' and `smerge-refined-removed', and new definition
 of `diff-removed'), insertions in green (new faces `diff-refine-added'
-and `smerge-refined-added' and new definition of `diff-added').
+and `smerge-refined-added', and new definition of `diff-added').
 
+---
 *** The variable `diff-use-changed-face' defines whether to use the
 face `diff-changed', or `diff-removed' and `diff-added' to highlight
 changes in context diffs.
 
-*** The new command `diff-remove-trailing-whitespace' fixes trailing
-whitespace problems introduced by the diff.
++++
+*** The new command `diff-remove-trailing-whitespace' removes trailing
+whitespace introduced by a diff.
 
 ** Dired
 +++