Add markup and copy for open-source community section

* Add basic style layout for the community section
* Add community icons
* Change layout of the community section
* Add button to section and clean up responsive style
* Uncomment social links in landing page
* Move stylesheets to modules folder
* Add global nav partial to index and featured social media links
* Remove community icons and restructure community section
* Add width to subtitle, call in locales, and reduce font size
* Reduce footer p size