3:2 image sizing

elections/blocks.py

elections/migrations/0010_alter_electionshomepage_content.py

shared/static/styleguide2/main.css

shared/static/styleguide2/main.js

shared/static/styleguide2/pirati-ui.svg

...includes/molecules/articles/article_timeline_preview.html

...plates/styleguide2/includes/molecules/boxes/card_box.html

.../styleguide2/includes/molecules/program/card_program.html