Clarify `checkdoc-max-keyref-before-warn` docstring

* lisp/emacs-lisp/checkdoc.el (checkdoc-max-keyref-before-warn): Clarify
and reflow docstring.  Fix warning about overly long docstring.

(cherry picked from commit 9fcee3c1d1eb6ce735dc69ee77b0c81900c19c3d)

diff --git a/lisp/emacs-lisp/checkdoc.el b/lisp/emacs-lisp/checkdoc.el
index bdb4896a6d1f8e8bbcdffff9f776735c74bbb22a..4880e710b55e8c9b622ec49b57ab4adb30c57ab3 100644 (file)
--- a/lisp/emacs-lisp/checkdoc.el
+++ b/lisp/emacs-lisp/checkdoc.el
@@ -262,14 +262,15 @@ with these words enabled."
 ;;;###autoload(put 'checkdoc-ispell-list-words 'safe-local-variable #'list-of-strings-p)
 
 (defcustom checkdoc-max-keyref-before-warn nil
-  "If non-nil, number of \\\\=[command-to-keystroke] tokens allowed in a doc string.
-Any more than this and a warning is generated suggesting that the construct
-\\\\={mapvar} be used instead.  If the value is nil, never warn.
-
-It used to not be practical to use `\\\\=[...]' very many times,
-because display of the documentation string would become slow.
-This is not an issue on modern machines, unless you have
-thousands of substitutions."
+  "Maximum number of \\\\=[command-to-keystroke] tokens allowed in a doc string.
+
+Any more than this and a warning is generated suggesting that the
+construct \\\\={mapvar} be used instead.  If the value is nil, never
+warn.
+
+It used to be impractical to use `\\\\=[...]' very many times, because
+display of the documentation string would become slow.  This is not an
+issue on modern machines, unless you have thousands of substitutions."
   :type '(choice (const nil)
                  integer)
   :version "28.1")