project-prompter: Update the docstring for the recent change

* lisp/progmodes/project.el (project-prompter):
Update the docstring too (bug#70833).

(cherry picked from commit efaec5f61df967e2a4b85c5607f559f92f220ca9)

diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
index 15363c1db42d3e1093101645385571eca9b91760..cf4f0a5438c6a6c350db251a2092b1eed8d26934 100644 (file)
--- a/lisp/progmodes/project.el
+++ b/lisp/progmodes/project.el
@@ -199,7 +199,9 @@ When it is non-nil, `project-current' will always skip prompting too.")
 
 (defcustom project-prompter #'project-prompt-project-dir
   "Function to call to prompt for a project.
-Called with no arguments and should return a project root dir."
+The function is either called with no arguments or with one argument,
+which is the prompt string to use.  It should return a project root
+directory."
   :type '(choice (const :tag "Prompt for a project directory"
                         project-prompt-project-dir)
                  (const :tag "Prompt for a project name"