New article: Font styles & font fallback

Font styles & font fallback
https://www.w3.org/International/articles/typography/fontstyles.en.html

Provides a non-exhaustive set of examples where choice of a font style 
may have a practical application. The existence of these distinct 
styles, with their practical influence on the reading of the text, has 
implications for fonts on the Web – you would typically want to choose a 
fallback font that has the same style, if one is available. We look at 
some implications for generic fonts and fallback mechanisms near the end.