docs: readme about sync two repos

Author: goshander

README.md

@@ -40,3 +40,16 @@ npm run post-build
 4. Go to [datalens-landing](https://github.com/datalens-tech/landing/) repository and manually run `Deploy` workflow action: [link](https://github.com/datalens-tech/landing/actions/workflows/deploy.yml)
 
 5. GitHub workflow action at landing repository automatically pull new docs release, build and deploy landing and docs to [datalens.tech](https://datalens.tech) as GitHub pages 
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+## Sync with docs
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+1. Documentation is synchronized with the main repository: [link](https://github.com/yandex-cloud/docs)
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+2. If you want to update the documentation, you need to create a pull request in the main repository
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+3. After the pull request is merged, robot (`DataUI VCS Robot`) automatically sync changes from the main repository to the this DataLens docs repository
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+4. The `ru`, `en` folders at root and the `.yfm` file are synchronized and will be overwritten
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+5. If you need to make changes `.yfm` config file, you need to edit local `.yfm-dltech` file