Adding `evaluate` to the list of libraries required in generated notebooks
This PR is based on the discussion in [doc-builder/Add custom first cell #50](https://github.com/huggingface/doc-builder/pull/50#issuecomment-1359312952).
It modifies the config file that defines the contents of the first cell for the Colab notebooks generated from the doc pages. This change adds `evaluate` to the list of libraries that are installed in the first cell of every generated notebook. 
Currently, only `transformers` and `dataset` libraries are installed by default. However, many notebooks also require `evaluate`. See examples: 
https://huggingface.co/docs/transformers/tasks/sequence_classification
https://huggingface.co/docs/transformers/tasks/semantic_segmentation
_The documentation is not available anymore as the PR was closed or merged._<|||||>@sgugger No problem! I don't have permissions to merge though :)