[Documentation issue] Sequence to sequence models
Most models have their example docstrings appended using the `add_code_sample_docstrings` method. This method checks the name of the architecture, and according to its suffix, adds the corresponding sequence.

However, this isn't perfect with the difference between sequence-to-sequence and enc/dec only models, which can have the same suffix: `BertModel` and `MarianModel` have the same suffixes, but should not have the same docstrings, the latter needing `decoder_input_ids` in order to work.

I propose to return a different code sample according to the architecture type (seq-to-seq vs enc/dec). The signature of the method that updates the code sample is the following:

https://github.com/huggingface/transformers/blob/2d458b2c7d6fb1dd5b2361938d1b5bd4c2106479/src/transformers/file_utils.py#L884-L886

There are in my opinion two ways to go about it:

- We can infer the type from the `output_type`. We've mentioned some while ago that having inheritance with model outputs and being able to identify categories of outputs from their classes would make sense for a potential pipeline-v2 implementation, this could be implemented here to detect if a model is seq-2-seq or not.
- We could add another argument to the signature too mention if it's seq-2-seq or not. However, this isn't very future-proof and can result in increased complexity if we ever need an additional separation across architectures.

@patrickvonplaten @sgugger @patil-suraj looking forward to your feedback. I tend to prefer the first option even if it requires a bit more work.

Related issue: https://github.com/huggingface/transformers/issues/10368
Option 1) seems the way to go for me as well here!<|||||>Said the same in private but realized I didn't put it here. So option 1 it is!<|||||>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/master/CONTRIBUTING.md) are likely to be ignored.<|||||>Don't close this one robot!<|||||>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/master/CONTRIBUTING.md) are likely to be ignored.