QUICKSTART: minor tweak

It was found out during the "from scratch" walkthrough
over http://altlinux.org/m-p with a new user that the
proposed test build run isn't clear regarding the proper
current working directory (wiki refers to QUICKSTART
copy over at http://git.altlinux.org, and this file has
been written with assumption that it's being read from
within the repository's toplevel directory; the resulting
context isn't consistent in that regard).

QUICKSTART

@@ -30,7 +30,7 @@ $ git config --global user.name "My Name"
 $ mkdir -p ~/out ~/tmp
 ----
 
-тестовая сборка::
+тестовая сборка (в каталоге mkimage-profiles)::
 ----
 $ make syslinux.iso
 ----