Yank items selected from kill-ring using completion and minibuffer history

Yank items selected from kill-ring using completion and minibuffer history

* doc/emacs/killing.texi (Earlier Kills): Document standalone M-y.

* doc/emacs/search.texi (Isearch Yank): Explain standalone M-y.

* doc/lispref/text.texi (Yank Commands): Soften the wording of
yank after another yank.

* lisp/delsel.el: Put 'yank' property on yank-pop and yank-from-kill-ring.

* lisp/isearch.el (isearch-yank-pop): Use with-isearch-suspended
and read-from-kill-ring to read a string from the kill-ring and
append it to the search string.

* lisp/simple.el (yank-pop): Call yank-from-kill-ring and
read-from-kill-ring when last-command is not 'yank' instead of
signaling an error.  Remove "*" from interactive spec.  Update docstring.
(read-from-kill-ring): New function.
(yank-from-kill-ring): New command.

https://lists.gnu.org/archive/html/emacs-devel/2020-11/msg00801.html