Improve 'compilation-hidden-output' docstring

* lisp/progmodes/compile.el (compilation-hidden-output): Escape
the newline so the example value is more suitable for copying.

(cherry picked from commit a73d08bb67a3562da42ea929df01eb1fb0c17b99)

diff --git a/lisp/progmodes/compile.el b/lisp/progmodes/compile.el
index a13437e0b377f60620e5822af1860ae9bdcc3184..659b89971bbf2327aafe6d043638edb897465161 100644 (file)
--- a/lisp/progmodes/compile.el
+++ b/lisp/progmodes/compile.el
@@ -95,8 +95,8 @@ like.
 For instance, to hide the verbose output from recursive
 makefiles, you can say something like:
 
-  (setq compilation-hidden-output
-        \\='(\"^make[^\n]+\n\"))"
+  (setopt compilation-hidden-output
+          \\='(\"^make[^\\n]+\\n\"))"
   :type '(choice regexp
                  (repeat regexp))
   :version "29.1")