Add python-sdk.md file on PR to docs

[alexdrydew]

Toloka/docs repository stores python-sdk.md file in docs directory. It is unwanted to also have it in this repository's docs. The solution is to add this file to docs/toc.yaml in the GitHub action.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [x] Documentation and examples improvement (changes affected documentation and/or examples)

Checklist:

• [x] I have read the CONTRIBUTING document.
• [x] I hereby agree to the terms of the CLA available at: https://yandex.ru/legal/cla/?lang=en
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• [x] All new and existing tests passed.