add perplexity evaluation result

README.md

@@ -12,4 +12,6 @@ base_model_relation: quantized
 
 This is an AMD Quark-quantized GLM-4.5 Air in fp8. Quantized on and for GFX1100 cards, in this case 2x W7900. 
 
-This is my first quantized model and I'm still evaluating. It was calibrated with wikitext; assuming success, a future iteration will be calibrated on other datasets.
+This is my first quantized model and I'm still evaluating. It was calibrated with wikitext; assuming success, a future iteration will be calibrated on other datasets.
+
+Quantized perplexity on wikitext: 4.96421480178833