Move yoga docs into docs folder on master branch

Summary: Move yoga docs into master branch so that pull requests are able to include doc updates as part of other changes.

Reviewed By: JoelMarcey

Differential Revision: D4365700

fbshipit-source-id: 2f46a88974104c454c00bcdf1257abb5c4075a68

docs/_includes/social_plugins.html

@@ -0,0 +1,24 @@
+<a
+  href="https://twitter.com/share"
+  class="twitter-share-button"
+  data-url="http://facebook.github.io/fresco{{ page.url }}"
+  data-text="Fresco | {{ page.title }}"
+  data-hashtags="fresco">Tweet</a>
+<div
+  class="fb-like"
+  data-href="http://facebook.github.io/fresco{{ page.url }}"
+  data-layout="standard"
+  data-action="like"
+  data-show-faces="true"
+  data-share="true"></div>
+
+<div id="fb-root"></div>
+<script>(function(d, s, id) {
+  var js, fjs = d.getElementsByTagName(s)[0];
+  if (d.getElementById(id)) return;
+  js = d.createElement(s); js.id = id;
+  js.src = "//connect.facebook.net/en_US/sdk.js#xfbml=1&version=v2.0";
+  fjs.parentNode.insertBefore(js, fjs);
+}(document, 'script', 'facebook-jssdk'));</script>
+
+<script>!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+'://platform.twitter.com/widgets.js';fjs.parentNode.insertBefore(js,fjs);}}(document, 'script', 'twitter-wjs');</script>