emacs-28 63abe97: Document minibuffer-default-prompt-format in manual

[Stefan Kangas]

branch: emacs-28
commit 63abe976ce65e42d67730d0577854867bc83e69c
Author: Stefan Kangas <stefan@marxist.se>
Commit: Stefan Kangas <stefan@marxist.se>

    Document minibuffer-default-prompt-format in manual
    
    * doc/emacs/mini.texi (Basic Minibuffer): Mention
    minibuffer-default-prompt-format.  (Bug#50935)
---
 doc/emacs/mini.texi | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/doc/emacs/mini.texi b/doc/emacs/mini.texi
index 6dcee3f..b0f6e42 100644
--- a/doc/emacs/mini.texi
+++ b/doc/emacs/mini.texi
@@ -41,11 +41,14 @@ Alternatively, you can type @kbd{C-g} to exit the 
minibuffer by
 canceling the command asking for the argument (@pxref{Quitting}).
 
 @cindex default argument
+@vindex minibuffer-default-prompt-format
   Sometimes, the prompt shows a @dfn{default argument}, inside
 parentheses before the colon.  This default will be used as the
 argument if you just type @key{RET}.  For example, commands that read
 buffer names usually show a buffer name as the default; you can type
-@key{RET} to operate on that default buffer.
+@key{RET} to operate on that default buffer.  You can customize how
+the default argument is shown with the user option
+@code{minibuffer-default-prompt-format}.
 
 @cindex Minibuffer Electric Default mode
 @cindex mode, Minibuffer Electric Default