Librarian Bot: Update dataset YAML metadata for model

This is a pull request to add a dataset, [`ConvLab/tm1`](https://huggingface.co/datasets/ConvLab/tm1), to the metadata for your model (defined in the `YAML` block of your model's `README.md`).
The pull request was made by [librarian-bot](https://huggingface.co/librarian-bot) and used a combination of rules and/or machine learning to suggest this additional metadata.
If this suggestion is incorrect, feel free to close this pull request.

Librarian Bot was made by [@davanstrien](https://huggingface.co/davanstrien); feel free to get in touch with feedback.

README.md

@@ -1,3 +1,6 @@
+---
+datasets: ConvLab/tm1
+---
 # gpt2-medium-nlg-tm1_tm2_tm3
 
 This model is a fine-tuned version of [GPT2-medium](https://huggingface.co/gpt2-medium) on [TaskMaster1](https://huggingface.co/datasets/ConvLab/tm1), [TaskMaster2](https://huggingface.co/datasets/ConvLab/tm2) and [TaskMaster3](https://huggingface.co/datasets/ConvLab/tm3)