Add new help command 'describe-command'

* lisp/help-fns.el (describe-command): New command.
(help-fns--describe-function-or-command-prompt): New helper
function to prompt for a function or function.  (Bug#46627)
(describe-function): Use above new helper function.

* lisp/help.el (help-map): Bind above new command to `C-h x'.
(help-for-help): Add this new command to the help summary.
* lisp/menu-bar.el (menu-bar-describe-menu): Add the new command to
the help menu.

* doc/emacs/help.texi (Help Summary, Name Help): Document
'describe-command', and update documentation on 'describe-function'.
* etc/tutorials/TUTORIAL: Change reference from 'describe-function' to
'describe-command'.

1 files changed, 3 insertions, 3 deletions

diff --git a/etc/tutorials/TUTORIAL b/etc/tutorials/TUTORIAL
index 6194e55ea35..dcdb61f23ec 100644
--- a/etc/tutorials/TUTORIAL
+++ b/etc/tutorials/TUTORIAL
@@ -1038,10 +1038,10 @@ then type C-x 1.
 
 Here are some other useful C-h options:
 
-   C-h f        Describe a function.  You type in the name of the
-                function.
+   C-h x        Describe a command.  You type in the name of the
+                command.
 
->> Try typing C-h f previous-line <Return>.
+>> Try typing C-h x previous-line <Return>.
    This displays all the information Emacs has about the
    function which implements the C-p command.