[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/timesformer.md

@@ -25,14 +25,15 @@ The abstract from the paper is the following:
 
 *We present a convolution-free approach to video classification built exclusively on self-attention over space and time. Our method, named "TimeSformer," adapts the standard Transformer architecture to video by enabling spatiotemporal feature learning directly from a sequence of frame-level patches. Our experimental study compares different self-attention schemes and suggests that "divided attention," where temporal attention and spatial attention are separately applied within each block, leads to the best video classification accuracy among the design choices considered. Despite the radically new design, TimeSformer achieves state-of-the-art results on several action recognition benchmarks, including the best reported accuracy on Kinetics-400 and Kinetics-600. Finally, compared to 3D convolutional networks, our model is faster to train, it can achieve dramatically higher test efficiency (at a small drop in accuracy), and it can also be applied to much longer video clips (over one minute long). Code and models are available at: [this https URL](https://github.com/facebookresearch/TimeSformer).*
 
-Tips:
-
-There are many pretrained variants. Select your pretrained model based on the dataset it is trained on. Moreover, the number of input frames per clip changes based on the model size so you should consider this parameter while selecting your pretrained model.
-
 This model was contributed by [fcakyon](https://huggingface.co/fcakyon).
 The original code can be found [here](https://github.com/facebookresearch/TimeSformer).
 
-## Documentation resources
+## Usage tips
+
+There are many pretrained variants. Select your pretrained model based on the dataset it is trained on. Moreover,
+the number of input frames per clip changes based on the model size so you should consider this parameter while selecting your pretrained model.
+
+## Resources
 
 - [Video classification task guide](../tasks/video_classification)