Add  document-question-answering in task_summary
# What does this PR do?

From issue #18926
This PR adds Document Question Answering summary to task_summary.mdx
It also provides an example using pipeline and this [model](https://huggingface.co/naver-clova-ix/donut-base-finetuned-docvqa)  

## Who can review?
@stevhliu 




_The documentation is not available anymore as the PR was closed or merged._<|||||>@stevhliu I only changed the docs. I don't know why the checks keep failing. It says it is having problems with ffmpeg?<|||||>Thank you so much for you help @stevhliu I think I should open a new PR. I made a mess here<|||||>I created a new pull request #23318 closing this PR