This patch adds examples to explain the new multiple store backend
declaration feature and how to use it. It covers both the case
where the user wants to declare multiple backends as well as just
one.
Change-Id: Ief8fea9d57422d05d36bf9b6946695249958aad9
Depends-on: I28a79ae36e673a3537ea16910d338666b65c80f7