bug#68703: update to lightning.texi to work w/ texi2any --pdf (with patch)

[Matt Wette]

The following changes to libguile/lightening/lightning.texi will allow 
it to be used with texi2any --pdf:

--- lightning.texi    2022-06-20 07:44:21.159880656 -0700
+++ lightning.texi-fixed    2024-01-24 12:07:27.621547717 -0800
@@ -83,22 +83,12 @@
 @ifnottex
 @node Top
 @top @lightning{}
-
-@iftex
-@macro comma
-@verbatim{|,|}
-@end macro
-@end iftex
-
-@ifnottex
-@macro comma
-@verb{|,|}
-@end macro
 @end ifnottex
 This document describes @value{TOPIC} the @lightning{} library for
 dynamic code generation.

+@ifnottex
 @menu
 * Overview::                What GNU lightning is
 * Installation::            Configuring and installing GNU lightning
--- lightning.texi	2022-06-20 07:44:21.159880656 -0700
+++ lightning.texi-fixed	2024-01-24 12:07:27.621547717 -0800
@@ -83,22 +83,12 @@
 @ifnottex
 @node Top
 @top @lightning{}
-
-@iftex
-@macro comma
-@verbatim{|,|}
-@end macro
-@end iftex
-
-@ifnottex
-@macro comma
-@verb{|,|}
-@end macro
 @end ifnottex
 
 This document describes @value{TOPIC} the @lightning{} library for
 dynamic code generation.
 
+@ifnottex
 @menu
 * Overview::                What GNU lightning is
 * Installation::            Configuring and installing GNU lightning