title: Alpine Add Package from Edge repository
body: <p>If I'm using Alpine 3.8, how can I add a specific package from the Alpine Edge repository? Is this even supported? There is no equivalent of backports, from what I can see.</p>
  
  <p>I want to add the new version of this: <a href="https://pkgs.alpinelinux.org/package/edge/community/armhf/librdkafka" rel="noreferrer">https://pkgs.alpinelinux.org/package/edge/community/armhf/librdkafka</a></p>
  
  <p>And not the older version in the 3.8 repo:
  <a href="https://pkgs.alpinelinux.org/package/v3.8/community/s390x/librdkafka" rel="noreferrer">https://pkgs.alpinelinux.org/package/v3.8/community/s390x/librdkafka</a></p>