typo in convert_to_litgpt command (#1807)

tutorials/download_model_weights.md

@@ -321,7 +321,7 @@ litgpt download <repo_id> \
 and then calling the `convert_hf_checkpoint` command:
 
 ```bash
-litgpt convert to_litgpt <repo_id>
+litgpt convert_to_litgpt <repo_id>
 ```
 
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