File _service of Package sile

<?xml version="1.0"?>
<services>
  <service mode="manual" name="download_url">
     <param name="protocol">https</param>
     <param name="host">github.com</param>
     <param name="path">/sile-typesetter/sile/releases/download/v0.15.7/sile-0.15.7.tar.zst</param>
  </service>
  <service name="cargo_vendor" mode="manual">
     <param name="src">sile*.tar.zst</param>
     <param name="compression">zst</param>
     <param name="update">true</param>
     <param name="filter">true</param>
  </service>
</services>