Create datadog-synthetics.yml

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🚨 IMPORTANT 🚨

• Please create an issue before creating a Pull Request
• Please use the following Git commit message style
  • Use future tense ("Adds feature" not "Added feature")
  • Use a "Fixes #xxx -" or "Closes #xxx -" prefix to auto-close the issue that your PR addresses
  • Limit the first line to 72 characters or less
  • Reference issues and pull requests liberally after the first line

↑👆 DELETE above before submitting 👆↑

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Description

Checklist

• I have followed the guidelines in the Contributing document
• My changes follow the coding style of this project
• My changes build without any errors or warnings
• My changes have been formatted and linted
• My changes include any required corresponding changes to the documentation (including CHANGELOG.md and README.md)
• My changes have been rebased and squashed to the minimal number (typically 1) of relevant commits
• My changes have a descriptive commit message with a short title, including a Fixes $XXX - or Closes #XXX - prefix to auto-close the issue that your PR addresses