doc string for `yank' should mention "paste"

[Drew Adams]

The doc string for `yank' should mention the commonly understood
"paste" operation as a (rough) synonym. Yanking is more than pasting,
but at a first approximation they are the same thing. Users should be able
to find `yank' when they do `M-x apropos-documentation paste'.

I checked the latest CVS simple.el, BTW.

In GNU Emacs 22.0.50.1 (i386-mingw-nt5.1.2600)
 of 2005-06-26 on NONIQPC
X server distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc
(3.3) --cflags -I../../jpeg-6b-3/include -I../../libpng-1.2.8/include -I../.
./tiff-3.6.1-2/include -I../../xpm-nox-4.2.0/include -I../../zlib-1.2.2/incl
ude'