feat(footer): add link to policies

Author: ashleygwilliams

app/templates/application.hbs

@@ -122,4 +122,6 @@
     <a href='http://doc.crates.io/guide.html'>Guide</a>
     <span class="sep">|</span>
     <a href='mailto:[email protected]'>Send us an email</a>
+    <span class="sep">|</span>
+    <a href='http://doc.crates.io/policies.html'>Policies</a>
 </div>