[Docs] Model_doc structure/clarity improvements (#26876)

* first batch of structure improvements for model_docs

* second batch of structure improvements for model_docs

* more structure improvements for model_docs

* more structure improvements for model_docs

* structure improvements for cv model_docs

* more structural refactoring

* addressed feedback about image processors

docs/source/en/model_doc/gptj.md

@@ -23,7 +23,7 @@ causal language model trained on [the Pile](https://pile.eleuther.ai/) dataset.
 
 This model was contributed by [Stella Biderman](https://huggingface.co/stellaathena).
 
-Tips:
+## Usage tips
 
 - To load [GPT-J](https://huggingface.co/EleutherAI/gpt-j-6B) in float32 one would need at least 2x model size
   RAM: 1x for initial weights and another 1x to load the checkpoint. So for GPT-J it would take at least 48GB
@@ -56,7 +56,7 @@ Tips:
   size, the tokenizer for [GPT-J](https://huggingface.co/EleutherAI/gpt-j-6B) contains 143 extra tokens
   `<|extratoken_1|>... <|extratoken_143|>`, so the `vocab_size` of tokenizer also becomes 50400.
 
-### Generation
+## Usage examples
 
 The [`~generation.GenerationMixin.generate`] method can be used to generate text using GPT-J
 model.
@@ -138,6 +138,9 @@ A list of official Hugging Face and community (indicated by 🌎) resources to h
 [[autodoc]] GPTJConfig
     - all
 
+<frameworkcontent>
+<pt>
+
 ## GPTJModel
 
 [[autodoc]] GPTJModel
@@ -158,6 +161,9 @@ A list of official Hugging Face and community (indicated by 🌎) resources to h
 [[autodoc]] GPTJForQuestionAnswering
     - forward
 
+</pt>
+<tf>
+
 ## TFGPTJModel
 
 [[autodoc]] TFGPTJModel
@@ -178,6 +184,9 @@ A list of official Hugging Face and community (indicated by 🌎) resources to h
 [[autodoc]] TFGPTJForQuestionAnswering
     - call
 
+</tf>
+<jax>
+
 ## FlaxGPTJModel
 
 [[autodoc]] FlaxGPTJModel
@@ -187,3 +196,5 @@ A list of official Hugging Face and community (indicated by 🌎) resources to h
 
 [[autodoc]] FlaxGPTJForCausalLM
     - __call__
+</jax>
+</frameworkcontent>