Update build/preview scripts to latest upstream versions
    
    This commit updates the `build.sh` and `preview.sh` scripts to use the
    latest versions committed to the fedora-docs/template repository. This
    is a minor change and will only impact local development, not production
    deployments.
    
    CC: @codeblock @t0xic0der @ramyaparimi @mattdm @riecatnor @misc
    
    Signed-off-by: Justin W. Flory (he/him) <git@jwf.io>