add hemdall install

Change-Id: I153cb95fd78eeca382814ddd28b738c65a2bb0bf
diff --git a/_samsung/samsunggalaxys20ultra.markdown b/_samsung/samsunggalaxys20ultra.markdown
index 61ca3d8..0132e5e 100644
--- a/_samsung/samsunggalaxys20ultra.markdown
+++ b/_samsung/samsunggalaxys20ultra.markdown
@@ -21,6 +21,8 @@
 
 {% include odininstall.html %}
 
+{% include heimdallinstall.html %}
+
 {% include twrpinstall.html %}
 
 {% include appinstall.html %}