Add link to cpu version of the web

app.py

@@ -428,6 +428,8 @@ with app:
     """)
     gr.Image("assets/readme-dimer-close-up.png")
     gr.Markdown(value="""
+        📣 **New!** The model now runs on [Zero GPU](https://huggingface.co/zero-gpu-explorers), which is currently in beta. Please see the [CPU-only version of PPIformer Web](https://huggingface.co/spaces/anton-bushuiev/PPIformer-CPU) if you experience any issues.
+
         [PPIformer](https://github.com/anton-bushuiev/PPIformer/tree/main) is a state-of-the-art predictor of the effects of mutations 
         on protein-protein interactions (PPIs), as quantified by the binding free energy changes (ddG). PPIformer was shown to successfully 
         identify known favourable mutations of the [staphylokinase thrombolytics](https://pubmed.ncbi.nlm.nih.gov/10942387/)