Extract DocSiteBuilder::Helpers#distro_map into _distro_map.yml file.
Merge pull request #45 from nhr/online_abstracted_distro_map

Extract DocSiteBuilder::Helpers#distro_map into _distro_map.yml file.
Removed Contributing topic from welcome page; fixed headings
Merge pull request #47 from CowboysFan/fix_welcome_page

Fix welcome page