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/plugins/like_button.html

@@ -0,0 +1,18 @@
+<div class="fb-like pluginWrapper likeButtonWrapper" data-layout="button_count" data-action="like" data-show-faces="true" data-share="true"></div>
+<script>
+  window.fbAsyncInit = function() {
+  FB.init({
+    appId      : '{{ site.fbappid }}',
+    xfbml      : true,
+    version    : 'v2.3'
+  });
+  };
+
+  (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";
+   fjs.parentNode.insertBefore(js, fjs);
+   }(document, 'script', 'facebook-jssdk'));
+</script>