improved instructions for in-place update

Signed-off-by: Leah Rowe <leah@libreboot.org>

site/news/update202308.md

@@ -90,6 +90,9 @@ use it in place, you could do this:
 ```
 cd lbmk/ # obviously, you need to be in lbmk
 rm -Rf coreboot/default grub seabios payload/grub payload/seabios
+cd coreboot/coreboot
+git pull
+cd ../../
 git pull
 ```
 Then simply build it as normal, and the new coreboot/grub/seabios will be