Use opencontainers labels.

skip-ci

Author: carlosperate

Dockerfile

@@ -1,6 +1,7 @@
 FROM ubuntu:16.04
 
-LABEL org.opencontainers.image.source https://github.com/mu-editor/docker-mu-appimage
+LABEL org.opencontainers.image.description="Docker image to create Mu Editor AppImage builds."
+LABEL org.opencontainers.image.source="https://github.com/mu-editor/docker-mu-appimage"
 
 # Installing build tools, git, python3 and setting it as the default python
 ENV DEBIAN_FRONTEND=noninteractive