docs: update site.mk

docs/site-example/site.mk

@@ -11,6 +11,7 @@ GLUON_SITE_PACKAGES := \
 	gluon-autoupdater \
 	gluon-config-mode-autoupdater \
 	gluon-config-mode-contact-info \
+	gluon-config-mode-core \
 	gluon-config-mode-geo-location \
 	gluon-config-mode-hostname \
 	gluon-config-mode-mesh-vpn \
@@ -22,6 +23,7 @@ GLUON_SITE_PACKAGES := \
 	gluon-next-node \
 	gluon-mesh-vpn-fastd \
 	gluon-radvd \
+	gluon-setup-mode \
 	gluon-status-page \
 	haveged \
 	iptables \