Add Cosmos3 family tree graph

Adds the Cosmos3 product and examples lineage graph to the model overview, following the format used by the recent Cosmos3 Nano simulation model cards. Please review the graph and lineage description.

README.md

@@ -23,6 +23,10 @@ tags:
 
 # Model Overview: Cosmos3-Super-Text2Image
 
+![Cosmos3 product and examples lineage highlighting Cosmos3-Super-Text2Image](images/cosmos3-super-text2image-graph.png)
+
+The highlighted checkpoint, Cosmos3-Super-Text2Image, is a post-trained text-to-image variant of the Cosmos3-Super base model.
+
 ## Description
 
 Cosmos3 is a collection of Omnimodal world models capable of generating dynamic, high-quality video, image, audio, and action commands from combinations of text, image, video, and action trajectory inputs. It serves as a foundational building block for a broad range of Physical AI applications and research spanning world understanding, world generation, simulation, and embodied policy learning.