Install and activate Polylang plugin

Reactivate the Polylang plugin now that the saving issues have been fixed.

requested review from @crdeoliv and @vasvi

approved this merge request

added 2 commits

• 82cba791 - 1 commit from branch master
• f87a35bb - Install and activate Polylang plugin

Compare with previous version

enabled an automatic merge when all merge checks for f87a35bb pass