bug#68164: Documentation fix for doc/emacs/custom.texi - missing escape for @

[Jens Quade]

Hi,

here is a short patch for a minor problem in the Customization chapter, the @ 
is missing in the rendered documentation if it isn’t escaped:



diff --git a/doc/emacs/custom.texi b/doc/emacs/custom.texi
index 3be332e087f..95fd5901ccf 100644
--- a/doc/emacs/custom.texi
+++ b/doc/emacs/custom.texi
@@ -2065,7 +2065,7 @@ Modifier Keys
 is no way to add two modifiers by using @kbd{C-x @@} twice for the
 same character, because the first one goes to work on the @kbd{C-x}.)
 You can similarly enter the Shift, Control, and Meta modifiers by
-using @kbd{C-x @ S}, @kbd{C-x @ c}, and @kbd{C-x @ m}, respectively,
+using @kbd{C-x @@ S}, @kbd{C-x @@ c}, and @kbd{C-x @@ m}, respectively,
 although this is rarely needed.

 @node Function Keys