provenpackagers: should be familiar with Fedora and EPEL updates policies
    
    Previously we didn't mention the Fedora and EPEL updates policies as
    things that provenpackagers should be familiar with, but they are quite
    important.  This change adds those links, and also converts those and
    other links from a long sentence to a bullet point list.  Outdated links
    are also switched to current ones.