[frontend] Add 'type=rpm-md' to .repo file template
    
    When using Zypper with copr repos, this needs to be added
    so that Zypper can properly consume the repository metadata.
    Zypper supports repo types of 'rpm-md', 'yast2', and 'plaindir'.
    More information is available in zypper(8) under "Repository
    Management".