Moved Best Practices out of Style Guidelines - Fixes #447

[PlagueHO]

Pull Request (PR) description

The Best Practices in StyleGuidelines were duplicated in the BestPractices document. This PR moves these into BestPractices and provides a link in the StyleGuidelines to these.

This Pull Request (PR) fixes the following issues

• Fixes #447

Task list

• [x] This PR changes documentation
• [ ] This PR changes DscResource.Template
  • [ ] Updated documentation as necessary in the TEMPLATE_README.md.
  • [ ] An descriptive entry has been added to the change log in the TEMPLATE_README.md.
• [ ] This PR changes Tests.Template
  • [ ] The template version number has been increased appropriately.
  • [ ] An descriptive entry has been added to the CHANGELOG.md under the Tests.Template folder.

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