improvement suggestion for upgrde47.html

In "Upgrading without install kernel" of the upgrade47.html document, 
the "Install new kernel(s) " section reads something along the lines of:
"Do this, and if you use a MP kernel you should have done that instead"

I also think that normally a bsd.sp kernel is created in the multiprocessor 
case.

To give a bit better guidance to the upgrader and in order to create the 
bsd.sp file, I'd like to propose the following replacement text:

Install new kernel(s) 
export RELEASEPATH=/usr/rel   # where you put the files
cd ${RELEASEPATH}

if you are using the single processor kernel, use:
rm /obsd ; ln /bsd /obsd && cp bsd /nbsd && mv /nbsd /bsd
cp bsd.rd bsd.mp /

if you are using the multiprocessor kernel, use:
rm /obsd ; ln /bsd /obsd && cp bsd.mp /nbsd && mv /nbsd /bsd
cp bsd.rd /
cp bsd /bsd.sp