Update normalize.css

[oliviertassinari]

Duplicate monospace reference.

[jonathantneal]

Thank you for looking through our code. Also, congrats on Material-UI.

The duplicated monospace, monospace in normalize.css is intentional. You may have noticed the reference for that declaration on line 88 which says “Correct the inheritance and scaling of font size in all browsers.”. For a description of why this is done, you can see Extended details and known issues.

I’m obligated to remind you that our Bug Reports also directs you to search issues, which would have shown you others who have also taken this rite of passage. While I’m closing this PR, I want you to know that I consider monospace, monospace issues and PRs a special example of curious and eager developers only trying to help. As I mentioned before, I genuinely appreciate the time you took to look over our code. I hope you’ll keep it up on any open source you use. :)

[oliviertassinari]

@jonathantneal Thanks for the quick answer. I'm gonna refer to stylelint/stylelint#2086. I was wondering about the need for the duplicated font. It seems to be a decade old issue. But I don't have any context on that fix. I guess it still make sens to have it.