15b90df prerequisites: Add more reference links for git and AsciiDoc

Authored and Committed by jflory7 3 years ago
    prerequisites: Add more reference links for git and AsciiDoc
    
    This commit adds an internal link to @bcotton's git for docs writer
    page, and also adds a link to the AsciiDoc quick reference syntax. It is
    reasonable to assume someone does not have prior experience with
    AsciiDoc since it is an uncommon markup language. So, this link provides
    a practical reference to learn the syntax. (I refer to this page almost
    every time I write Fedora Docs.)
    
    Signed-off-by: Justin W. Flory <git@jwf.io>