the electron PDF service has been live on German wikipedia since February, 2017. It is set as the default experience for rendering of single-article PDF's.
- add the electron PDF service as an option for rendering single-artcile PDF's (Download as PDF page)
- allow the electron PDF service to be the default option when printing individual PDF's (as the current implementation on mediawiki)
- ensure tracking in https://grafana.wikimedia.org/dashboard/db/mediawiki-electronpdfservice?orgId=1&from=1484922362966&to=1495290362970