Update img/media-types.dot

Co-authored-by: Brandon Mitchell <git@bmitch.net>
Signed-off-by: Sajay Antony <1821104+sajayantony@users.noreply.github.com>

Author: sajayantony

img/media-types.dot

@@ -14,7 +14,9 @@ digraph G {
   imageIndex -> manifest [label="1..*"]
   manifest -> config [label="1..1"]
   manifest -> layer [label="1..*"]
-  artifact -> manifest [label="1..1"] [constraint = false];
+  artifact -> manifest [label="0..1"] [constraint = false];
+  artifact -> artifact [label="0..1"];
+  manifest -> manifest [label="0..1"];
   artifact -> imageIndex [label="1..1"]
   artifact -> layer[label="1..*"]
 }