Change instances of 'Primer' to 'Origin' and update repo in config

Author: robbiemanson

_config.yml

@@ -15,4 +15,4 @@ sass:
   style: compressed
 
 github:
-  repo: https://github.com/primer/primer
+  repo: https://github.com/fac/origin

docs/_layouts/default.html

@@ -10,7 +10,7 @@
     <meta name="author" content="">
 
     <title>
-      {{ page.title }} &middot; Primer
+        {{ page.title }} &middot; Origin
     </title>
 
     <link rel="stylesheet" href="{{ site.baseurl }}/docs.css">
@@ -25,7 +25,7 @@
       <div class="container">
         <a href="{{ site.baseurl }}/" class="masthead-logo">
           <span class="mega-octicon octicon-package"></span>
-          Primer
+          Origin
         </a>
 
         <nav class="masthead-nav">
@@ -40,7 +40,7 @@
     {% if page.title == "Home" %}
       <div class="jumbotron">
         <div class="container">
-          <h1>Primer</h1>
+          <h1>Origin</h1>
           <p>The CSS toolkit and guidelines that power GitHub.</p>
 
           <a href="{{ site.baseurl }}/scaffolding/" class="btn btn-reverse">