Add middleman-blog to project
Introduce middleman-blog and refactor layouts.
Add first blog article and work on article list and article layout.
Cleanup blog, tag and calendar pages.
Merge branch 'feature/add-blog' into develop

* feature/add-blog:
  Cleanup blog, tag and calendar pages.
  Add first blog article and work on article list and article layout.
  Introduce middleman-blog and refactor layouts.
  Add middleman-blog to project