Use the build-scripts dir from the upstream repo for dockerfile

Signed-off-by: Patrick Uiterwijk <patrick@puiterwijk.org>

roles/openshift-apps/docsbuilding/templates/buildconfig.yml

@@ -9,10 +9,9 @@ spec:
   strategy:
     type: Docker
   source:
-    dockerfile: |-
-      FROM fedora:latest
-      RUN dnf -y module install nodejs:10 && dnf clean all
-      RUN npm i -g @antora/cli@2.0 @antora/site-generator-default@2.0
+    git:
+      uri: "https://pagure.io/fedora-docs/docs-fp-o.git"
+    contextDir: "build-scripts"
   output:
     to:
       kind: ImageStreamTag