docs: Add Turkish translation (docs/tr.md)

Hi @teivah ,

I would like to contribute to the project by translating the documentation into Turkish (similar to zh.md and pt-br.md).

I plan to work on this in small PRs to make the review process easier. I will start by creating docs/tr.md.

Please let me know if anyone else is currently working on this or if you have specific guidelines for new language additions.

Thanks!