Move 'kdb-macro-redisplay' key binding

* doc/emacs/kmacro.texi (Basic Keyboard Macro): Adjust.

* lisp/kmacro.el (kmacro-keymap): Move 'kdb-macro-redisplay' to
`C-x C-k d' since upper-case letters are reserved for users (bug#50727).

doc/emacs/kmacro.texi

@@ -180,11 +180,11 @@ define it, so @kbd{C-u 4 C-x )} executes the macro immediately 3
 additional times.
 
 @findex kdb-macro-redisplay
-@kindex C-x C-k Q
+@kindex C-x C-k d
   While executing a long-running keyboard macro, it can sometimes be
 useful to trigger a redisplay (to show how far we've gotten).  The
-@kbd{C-x C-k Q} can be used for this.  As a not very useful example,
-@kbd{C-x ( M-f C-x C-k Q C-x )} will create a macro that will
+@kbd{C-x C-k d} command can be used for this.  As a not very useful
+example, @kbd{C-x ( M-f C-x C-k d C-x )} will create a macro that will
 redisplay once per iteration when saying @kbd{C-u 42 C-x e}.
 
 @node Keyboard Macro Ring

etc/NEWS

@@ -1047,7 +1047,8 @@ Set the variable 'auto-save-visited-mode' buffer-locally to nil to
 achieve that.
 
 +++
-** New command 'C-x C-k Q' to force redisplay in keyboard macros.
+** New command 'kdb-macro-redisplay to force redisplay in keyboard macros.
+This command is bound to 'C-x C-k d'.
 
 ---
 ** 'blink-cursor-mode' is now enabled by default regardless of the UI.

lisp/kmacro.el

@@ -172,7 +172,7 @@ macro to be executed before appending to it."
     (define-key map "\C-k" #'kmacro-end-or-call-macro-repeat)
     (define-key map "r"    #'apply-macro-to-region-lines)
     (define-key map "q"    #'kbd-macro-query)  ;; Like C-x q
-    (define-key map "Q"    #'kdb-macro-redisplay)
+    (define-key map "d"    #'kdb-macro-redisplay)
 
     ;; macro ring
     (define-key map "\C-n" #'kmacro-cycle-ring-next)