Add CANINE and TAPAS to doc tests
# What does this PR do?

Adds CANINE and TAPAS to the doc tests.
The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_16354). All of your documentation changes will be reflected on that endpoint.<|||||>Thank you working on this, @NielsRogge 

Do you think it's possible to:
- Add more realistic examples for `TapasForQuestionAnswering`, `TapasForSequenceClassification`, etc.
- Add expected output shape for `TapasModel` and make its docstring output the shape instead of the logits.

@patrickvonplaten Do you think it is good to (always) ask the contributors to change the docstrings of `ModelForXXX` to something more meaningful (i.e. instead of the logits), as my comments here above?

Or should I just review only the changes done in their PRs?<|||||>This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

Please note that issues that do not follow the [contributing guidelines](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md) are likely to be ignored.