[Docs]: v9 style handbook needs guidance on reset/normalize CSS

[GeoffCoxMSFT]

Area

React Components (https://react.fluentui.dev)

What kind of documentation issue are you reporting?

• [ ] Reporting a typo
• [ ] Reporting a documentation bug
• [x] Documentation improvement
• [ ] Documentation feedback

Is there a specific documentation page you are reporting?

https://github.com/microsoft/fluentui/blob/master/docs/react-v9/contributing/rfcs/react-components/styles-handbook.md

Description

Partner asked about whether or not to use a reset.css or normalize.css with Fluent v9 components - if that was still something recommended or not. Also whether or not to use the ms-grid styles from earlier versions for layout.

The style handbook could have a section on why v9 does not provide a reset/normalize, and information about using css grid/flex for layout.

Validations

• [x] Check that there isn't already an issue that requests the same feature to avoid creating a duplicate.