add calendar to euroweb page

calendar_utils/models.py

...grations/0046_donatehomepage_transparency_footer_items.py

donate/models.py

elections/blocks.py

elections/migrations/0024_electionssimplepage.py

...ns/migrations/0025_electionshomepage_calendar_and_more.py

elections/models.py

green_deal/migrations/0002_auto_20201208_1435.py

green_deal/migrations/0003_auto_20210107_1120.py

green_deal/migrations/0004_auto_20210110_2351.py

...grations/0008_alter_greendealhomepage_content_and_more.py

shared/static/styleguide2/main.css

shared/static/styleguide2/main.js

...2/includes/organisms/main_section/elections/calendar.html