Control auto-publishing comments on push with preference

Change-Id: Ibf6c61d8c34ee790ca7ed29a0fad0b5e81910f09

Documentation/intro-user.txt

diff --git a/Documentation/intro-user.txt b/Documentation/intro-user.txt
index 2c42d74..9aa0a3b 100644
--- a/Documentation/intro-user.txt
+++ b/Documentation/intro-user.txt
@@ -773,6 +773,12 @@
 and `Edit Config` buttons on the project screen, and the `Follow-Up`
 button on the change screen).
 
+- [[publish-comments-on-push]]`Publish Draft Comments When a Change Is Updated by Push`:
++
+Whether to publish any outstanding draft comments by default when pushing
+updates to open changes. This preference just sets the default; the behavior can
+still be overridden using a link:user-upload.html#publish-comments[push option].
+
 - [[use-flash]]`Use Flash Clipboard Widget`:
 +
 Whether the Flash clipboard widget should be used. If enabled and the Flash