[i18n-ar] Translated file : docs/source/ar/installation.md into Arabic

[AhmedAlmaghz]

What does this PR do?

Translated the docs/source/ar/installation.md file of the documentation to Arabic العربية. I use transformers for my side-project and wanted to contribute. As a beginner, this seemed appropriate.

Some questions:

• I can't access the pr documentation endpoint for Arabic العربية. Is there a missing step?
• I left all the other files alone after copying the English docs. Is this acceptable for future updates or should I add contents to the _toctree.yml only when translation is complete? Should I delete all other files for a cleaner review?
• In Arabic, people use both Transformer and المحولات to describe the model. However, as this is more of a product of HuggingFace I opted not to translate it. May you please let me know which you would prefer?

Thank you in advance for your review.

Part of #32435

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, Pull Request section?
• Was this discussed/approved via a Github issue or the forum ?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, and here are tips on formatting docstrings.
• Did you write any new necessary tests?

Who can review?

@stevhliu , @MKhalusova , @abodacs, may you please review this PR?

[abodacs]

@AhmedAlmaghz
شكرا على مجهودك

تمت المراجعة

[stevhliu]

Thanks! Once the toctree is merged in your other PR, you'll need to add this doc to the toctree.

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[AhmedAlmaghz]

Thank you @abodacs @stevhliu

[AhmedAlmaghz]

@abodacs
Next :

• Run inference with pipelines [i18n-ar] Translated file : docs/source/ar/pipeline_tutorial.md into Arabic #33065
• Write portable code with AutoClass [i18n-ar] Translated file : docs/source/ar/autoclass_tutorial.md into Arabic #33022
• Preprocess data [i18n-ar] Translated file : docs/source/ar/preprocessing.md into Arabic #33068
• Fine-tune a pretrained model [i18n-ar] Translated file : docs/source/ar/training.md into Arabic #33081
• Train with a script [i18n-ar] Translated file : docs/source/ar/run_scripts.md into Arabic #33070
• Set up distributed training with 🤗 Accelerate [i18n-ar] Translated file : docs/source/ar/accelerate.md into Arabic #33016
• Load and train adapters with 🤗 PEFT [i18n-ar] Translated file : docs/source/ar/peft.md into Arabic #33051
• Share your model [i18n-ar] Translated file : docs/source/ar/model_sharing.md into Arabic #33046
• Agents [i18n-ar] Translated file : docs/source/ar/agents.md into Arabic #33020
• Generation with LLMs [i18n-ar] Translated file : docs/source/ar/llm_tutorial.md into Arabic #33044
• Chatting with Transformers [i18n-ar] Translated file : docs/source/ar/conversations.md into Arabic #33029