"This theme is missing a 'content' region".?
Looks like you need to indent your region names 2 spaces. See https://www.drupal.org/node/2349827 for more information on defining a theme with an .info.yml file.

Also the link in your description is missing a closing  tag.  

You should also be quoting some of your strings.  There is a link on the page above to read the quick introduction to the YAML file format that takes you to http://symfony.com/doc/current/components/yaml/yaml_format.html . That page provides good information on quoting strings.