Fix object detection2
Author: Narsil
Pull request: yes


# What does this PR do?

Fixes https://github.com/huggingface/transformers/pull/20776 better.

- Reverts the previous PR.

- The previous model was using a mix of LayoutLM and LayoutLMv2 leading to a bit of madness. The previous fix was wrong
because it made other pipelines try to load the feature extractor which might not have existed :(.

This fixes differently, by using another new models, and fixing it's config too.

`Narsil/layoutlmv3-finetuned-funsd` is a fork of `nielsr/layoutlmv3-finetuned-funsd` with the `tokenizer_config.json` fixed (to not use a Roberta tokenizer, but it's proper LayoutLMv3Tokenizer). 
Also modified the README.md to include examples in the widget, and force the pipeline_tag to be `object-detection`.
  
https://huggingface.co/Narsil/layoutlmv3-finetuned-funsd
![Screenshot from 2022-12-16 11-03-23](https://user-images.githubusercontent.com/204321/208074245-8f718e27-3864-42c5-aeae-558ff4fd2e0b.png)


<!--
Congratulations! You've made it this far! You're not quite done yet though.

Once merged, your PR is going to appear in the release notes with the title you set, so make sure it's a great title that fully reflects the extent of your awesome contribution.

Then, please replace this with a description of the change and which issue is fixed (if applicable). Please also include relevant motivation and context. List any dependencies (if any) that are required for this change.

Once you're done, someone will review your PR shortly (see the section "Who can review?" below to tag some potential reviewers). They may suggest changes to make the code even better. If no one reviewed your PR after a week has passed, don't hesitate to post a new comment @-mentioning the same persons---sometimes notifications get lost.
-->

<!-- Remove if not applicable -->

Fixes # (issue)


## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [ ] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#start-contributing-pull-requests),
      Pull Request section?
- [ ] Was this discussed/approved via a Github issue or the [forum](https://discuss.huggingface.co/)? Please add a link
      to it if that's the case.
- [ ] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/main/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/main/docs#writing-source-documentation).
- [ ] Did you write any new necessary tests?


## Who can review?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
members/contributors who may be interested in your PR.

<!-- Your PR will be replied to more quickly if you can figure out the right person to tag with @

 If you know how to use git blame, that is the easiest way, otherwise, here is a rough guide of **who to tag**.
 Please tag fewer than 3 people.

Models:

- text models: @ArthurZucker and @younesbelkada
- vision models: @amyeroberts and @NielsRogge
- speech models: @sanchit-gandhi

Library:

- flax: @sanchit-gandhi
- generate: @gante
- pipelines: @Narsil
- tensorflow: @gante and @Rocketknight1
- tokenizers: @ArthurZucker
- trainer: @sgugger

Integrations:

- deepspeed: @stas00
- ray/raytune: @richardliaw, @amogkam

Documentation: @sgugger and @stevhliu

HF projects:

- accelerate: [different repo](https://github.com/huggingface/accelerate)
- datasets: [different repo](https://github.com/huggingface/datasets)
- diffusers: [different repo](https://github.com/huggingface/diffusers)
- rust tokenizers: [different repo](https://github.com/huggingface/tokenizers)

Maintained examples (not research project or legacy):

- Flax: @sanchit-gandhi
- PyTorch: @sgugger
- TensorFlow: @Rocketknight1

 -->


Comments:
_The documentation is not available anymore as the PR was closed or merged._

> Thanks, looks great!
> 
> Since when is LayoutLM supported by the object detection pipeline? :D

https://github.com/huggingface/transformers/pull/20143