add hemdall install

Change-Id: I153cb95fd78eeca382814ddd28b738c65a2bb0bf
diff --git a/_samsung/samsunggalaxyj7exynos.markdown b/_samsung/samsunggalaxyj7exynos.markdown
index 0d2e1b1..df3d140 100644
--- a/_samsung/samsunggalaxyj7exynos.markdown
+++ b/_samsung/samsunggalaxyj7exynos.markdown
@@ -22,4 +22,6 @@
 
 {% include odininstall.html %}
 
+{% include heimdallinstall.html %}
+
 {% include ddinstall.html %}