Bug 1656078: Display description of introduction instead of title

In bug 1438894 the fields for the introduction
artefact were changed.
Now we need to use the description of the artefact
instead of the title to show the introduction text.

behatnotneeded

Change-Id: I00618b471bc3a1460824394c081773548e19f0b4
(cherry picked from commit 022c81b8)