Kickstart: Improve AsciiDoc syntax, add multi-line description lists
    
    This commit makes a few improvements and clean-ups to build on PR #9:
    
    * Drop note that kickstarts are not ready for public, given that we are
      about to submit the F34 Change proposal
    * Use multi-line description lists to order the steps for building the
      ISO with Lorax (they are pretty!)
    * Leave `livecd-creator` instructions at the end, since we are trying to
      move away from that method
    * Misc. AsciiDoc formatting and syntax improvements
    
    Closes i3-sig/Fedora-i3-Spin#25.
    
    Signed-off-by: Justin W. Flory (he/him) <git@jwf.io>