website_back2top/views/templates.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
  <data>

    <template id="assets_frontend_back2top" inherit_id="website.assets_frontend" active="True" customize_show="True" name="Back2top">
      <xpath expr="." position="inside">
          <link rel='stylesheet' href='/website_back2top/static/src/css/website_scroll_back2top.css'/>
          <script type="text/javascript" src="/website_back2top/static/src/js/website_scroll_back2top.js"></script>
      </xpath>
    </template>
  </data>
</openerp>