Enable doc in Spanish (#16518)

* Reorganize doc for multilingual support

* Fix style

* Style

* Toc trees

* Adapt templates

docs/source/en/model_doc/auto.mdx

@@ -0,0 +1,263 @@
+<!--Copyright 2020 The HuggingFace Team. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+the License. You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+specific language governing permissions and limitations under the License.
+-->
+
+# Auto Classes
+
+In many cases, the architecture you want to use can be guessed from the name or the path of the pretrained model you
+are supplying to the `from_pretrained()` method. AutoClasses are here to do this job for you so that you
+automatically retrieve the relevant model given the name/path to the pretrained weights/config/vocabulary.
+
+Instantiating one of [`AutoConfig`], [`AutoModel`], and
+[`AutoTokenizer`] will directly create a class of the relevant architecture. For instance
+
+
+```python
+model = AutoModel.from_pretrained("bert-base-cased")
+```
+
+will create a model that is an instance of [`BertModel`].
+
+There is one class of `AutoModel` for each task, and for each backend (PyTorch, TensorFlow, or Flax).
+
+## Extending the Auto Classes
+
+Each of the auto classes has a method to be extended with your custom classes. For instance, if you have defined a
+custom class of model `NewModel`, make sure you have a `NewModelConfig` then you can add those to the auto
+classes like this:
+
+```python
+from transformers import AutoConfig, AutoModel
+
+AutoConfig.register("new-model", NewModelConfig)
+AutoModel.register(NewModelConfig, NewModel)
+```
+
+You will then be able to use the auto classes like you would usually do!
+
+<Tip warning={true}>
+
+If your `NewModelConfig` is a subclass of [`~transformer.PretrainedConfig`], make sure its
+`model_type` attribute is set to the same key you use when registering the config (here `"new-model"`).
+
+Likewise, if your `NewModel` is a subclass of [`PreTrainedModel`], make sure its
+`config_class` attribute is set to the same class you use when registering the model (here
+`NewModelConfig`).
+
+</Tip>
+
+## AutoConfig
+
+[[autodoc]] AutoConfig
+
+## AutoTokenizer
+
+[[autodoc]] AutoTokenizer
+
+## AutoFeatureExtractor
+
+[[autodoc]] AutoFeatureExtractor
+
+## AutoProcessor
+
+[[autodoc]] AutoProcessor
+
+## AutoModel
+
+[[autodoc]] AutoModel
+
+## AutoModelForPreTraining
+
+[[autodoc]] AutoModelForPreTraining
+
+## AutoModelForCausalLM
+
+[[autodoc]] AutoModelForCausalLM
+
+## AutoModelForMaskedLM
+
+[[autodoc]] AutoModelForMaskedLM
+
+## AutoModelForSeq2SeqLM
+
+[[autodoc]] AutoModelForSeq2SeqLM
+
+## AutoModelForSequenceClassification
+
+[[autodoc]] AutoModelForSequenceClassification
+
+## AutoModelForMultipleChoice
+
+[[autodoc]] AutoModelForMultipleChoice
+
+## AutoModelForNextSentencePrediction
+
+[[autodoc]] AutoModelForNextSentencePrediction
+
+## AutoModelForTokenClassification
+
+[[autodoc]] AutoModelForTokenClassification
+
+## AutoModelForQuestionAnswering
+
+[[autodoc]] AutoModelForQuestionAnswering
+
+## AutoModelForTableQuestionAnswering
+
+[[autodoc]] AutoModelForTableQuestionAnswering
+
+## AutoModelForImageClassification
+
+[[autodoc]] AutoModelForImageClassification
+
+## AutoModelForVision2Seq
+
+[[autodoc]] AutoModelForVision2Seq
+
+## AutoModelForAudioClassification
+
+[[autodoc]] AutoModelForAudioClassification
+
+## AutoModelForAudioFrameClassification
+
+[[autodoc]] AutoModelForAudioFrameClassification
+
+## AutoModelForCTC
+
+[[autodoc]] AutoModelForCTC
+
+## AutoModelForSpeechSeq2Seq
+
+[[autodoc]] AutoModelForSpeechSeq2Seq
+
+## AutoModelForAudioXVector
+
+[[autodoc]] AutoModelForAudioXVector
+
+## AutoModelForMaskedImageModeling
+
+[[autodoc]] AutoModelForMaskedImageModeling
+
+## AutoModelForObjectDetection
+
+[[autodoc]] AutoModelForObjectDetection
+
+## AutoModelForImageSegmentation
+
+[[autodoc]] AutoModelForImageSegmentation
+
+## AutoModelForSemanticSegmentation
+
+[[autodoc]] AutoModelForSemanticSegmentation
+
+## AutoModelForInstanceSegmentation
+
+[[autodoc]] AutoModelForInstanceSegmentation
+
+## TFAutoModel
+
+[[autodoc]] TFAutoModel
+
+## TFAutoModelForPreTraining
+
+[[autodoc]] TFAutoModelForPreTraining
+
+## TFAutoModelForCausalLM
+
+[[autodoc]] TFAutoModelForCausalLM
+
+## TFAutoModelForImageClassification
+
+[[autodoc]] TFAutoModelForImageClassification
+
+## TFAutoModelForMaskedLM
+
+[[autodoc]] TFAutoModelForMaskedLM
+
+## TFAutoModelForSeq2SeqLM
+
+[[autodoc]] TFAutoModelForSeq2SeqLM
+
+## TFAutoModelForSequenceClassification
+
+[[autodoc]] TFAutoModelForSequenceClassification
+
+## TFAutoModelForMultipleChoice
+
+[[autodoc]] TFAutoModelForMultipleChoice
+
+## TFAutoModelForTableQuestionAnswering
+
+[[autodoc]] TFAutoModelForTableQuestionAnswering
+
+## TFAutoModelForTokenClassification
+
+[[autodoc]] TFAutoModelForTokenClassification
+
+## TFAutoModelForQuestionAnswering
+
+[[autodoc]] TFAutoModelForQuestionAnswering
+
+## TFAutoModelForVision2Seq
+
+[[autodoc]] TFAutoModelForVision2Seq
+
+## TFAutoModelForSpeechSeq2Seq
+
+[[autodoc]] TFAutoModelForSpeechSeq2Seq
+
+## FlaxAutoModel
+
+[[autodoc]] FlaxAutoModel
+
+## FlaxAutoModelForCausalLM
+
+[[autodoc]] FlaxAutoModelForCausalLM
+
+## FlaxAutoModelForPreTraining
+
+[[autodoc]] FlaxAutoModelForPreTraining
+
+## FlaxAutoModelForMaskedLM
+
+[[autodoc]] FlaxAutoModelForMaskedLM
+
+## FlaxAutoModelForSeq2SeqLM
+
+[[autodoc]] FlaxAutoModelForSeq2SeqLM
+
+## FlaxAutoModelForSequenceClassification
+
+[[autodoc]] FlaxAutoModelForSequenceClassification
+
+## FlaxAutoModelForQuestionAnswering
+
+[[autodoc]] FlaxAutoModelForQuestionAnswering
+
+## FlaxAutoModelForTokenClassification
+
+[[autodoc]] FlaxAutoModelForTokenClassification
+
+## FlaxAutoModelForMultipleChoice
+
+[[autodoc]] FlaxAutoModelForMultipleChoice
+
+## FlaxAutoModelForNextSentencePrediction
+
+[[autodoc]] FlaxAutoModelForNextSentencePrediction
+
+## FlaxAutoModelForImageClassification
+
+[[autodoc]] FlaxAutoModelForImageClassification
+
+## FlaxAutoModelForVision2Seq
+
+[[autodoc]] FlaxAutoModelForVision2Seq