Update README.md with new model card content

README.md

@@ -92,7 +92,7 @@ gpt2_lm.generate(prompt)
 Call `fit()` on a single batch.
 ```python
 features = ["The quick brown fox jumped.", "I forgot my homework."]
-gpt2_lm = keras_hub.models.GPT2CausalLM.from_preset("gpt2_base_en")
+gpt2_lm = keras_hub.models.GPT2CausalLM.from_preset("gpt2_extra_large_en")
 gpt2_lm.fit(x=features, batch_size=2)
 ```
 
@@ -158,7 +158,7 @@ gpt2_lm.generate(prompt)
 Call `fit()` on a single batch.
 ```python
 features = ["The quick brown fox jumped.", "I forgot my homework."]
-gpt2_lm = keras_hub.models.GPT2CausalLM.from_preset("gpt2_base_en")
+gpt2_lm = keras_hub.models.GPT2CausalLM.from_preset("hf://keras/gpt2_extra_large_en")
 gpt2_lm.fit(x=features, batch_size=2)
 ```