Publish whitelist

per

#604 (comment)

it appears i have a misunderstanding of what this is:

http://pages.github.com/versions

my understanding is that page is a list of all plugins that are whitelisted by GitHub pages.

if thats not the case - can we get a public list of those

or are we expected to just look here:

pages-gem/lib/github-pages/plugins.rb

Lines 22 to 41 in fb5c3f2

	jekyll-coffeescript
	jekyll-commonmark-ghpages
	jekyll-feed
	jekyll-gist
	jekyll-github-metadata
	jekyll-paginate
	jekyll-redirect-from
	jekyll-seo-tag
	jekyll-sitemap
	jekyll-avatar
	jemoji
	jekyll-mentions
	jekyll-relative-links
	jekyll-optional-front-matter
	jekyll-readme-index
	jekyll-default-layout
	jekyll-titles-from-headings
	jekyll-include-cache
	jekyll-octicons
	jekyll-remote-theme