clean headings (#2378)

app/controllers/admin/communication/blocks_controller.rb

app/models/ability/admin.rb

app/models/ability/author.rb

app/models/ability/program_manager.rb

app/models/ability/teacher.rb

app/models/ability/website_manager.rb

app/models/communication/block.rb

app/models/communication/block/with_heading_ranks.rb

app/models/communication/website/page/localization.rb

app/models/concerns/as_localization.rb

...ervices/importers/api/osuny/communication/website/base.rb

app/views/admin/communication/contents/_static.json.jbuilder

config/locales/communication/contents/en.yml

config/locales/communication/contents/fr.yml

config/locales/communication/en.yml

config/locales/communication/fr.yml

config/locales/education/en.yml

config/routes/admin/communication.rb