change style.css to main.css

[therealedsheenan]

By changing style.css to main.css, this will solve the development environment issue.
While running bundle exec jekyll serve, when the developer change some files, for some reason the server would not reload the updated style.css. When the page is reloaded the style.css that was generated would be from another source. bootstrap-ish css.

By renaming the style.css to main.css the server will always look for the right .css file that was updated.