Add base model metadata

This metadata specifies which model was used as a base model for fine-tuning and allows users to have a better understanding of the lineage of models on the Hub :)

README.md

@@ -10,6 +10,7 @@ datasets:
 - LDJnr/LessWrong-Amplify-Instruct
 - LDJnr/Pure-Dove
 - LDJnr/Verified-Camel
+base_model: 01-ai/Yi-34B-200K
 ---
 
 ## **Nous-Capybara-34B V1.9**