Integrate markdown docs with client generated docs

[erinreeves]

Use Jekyll via CircleCI to generate a static site representing our onestop/docs directory in the onestop repo.

• [ ] Have Jekyll in CircleCI generate a static site https://jekyllrb.com/docs/continuous-integration/circleci/
• [ ] Specify to have jekyll to use css we use for the client app. You need to place the css in your site folder and they’ll copy across to the built site.

Tutorial/example: https://jekyllrb.com/docs/step-by-step/07-assets/

Directory structure: https://jekyllrb.com/docs/structure/