DEPRECATION WARNING: Single arity template handlers are deprecated. Template handlers must now accept two parameters, the view object and the source for the view object.
Change:
  >> KramdownRails::TemplateHandler.call(template)
To:
  >> KramdownRails::TemplateHandler.call(template, source)
 (called from <top (required)> at /rails-app-dir/config/application.rb:7)
DEPRECATION WARNING: Single arity template handlers are deprecated. Template handlers must now accept two parameters, the view object and the source for the view object.
Change:
  >> KramdownRails::TemplateHandler.call(template)
To:
  >> KramdownRails::TemplateHandler.call(template, source)
 (called from <top (required)> at /rails-app-dir/config/application.rb:7)
Loading development environment (Rails 6.0.0)