Updated the Node version to version 12
Antora 2.3.x states that you should be using Node version 12 with Antora, but the antora/antora:2.3.4
docker image was still based on Node 10.
This merge requests bumps the Node version to 12.
Antora 2.3.x states that you should be using Node version 12 with Antora, but the antora/antora:2.3.4
docker image was still based on Node 10.
This merge requests bumps the Node version to 12.