message: Add target name to platform link
diff: <a href="#" class="pure-menu-link"><i class="fa fa-fw fa-gears"></i><span class="title"> Platform</span></a>
  <ul class="pure-menu-children">
  {{#each doc_targets}}
  - <li class="pure-menu-item"><a href="/{{../../content.crate_details.name}}/{{../../content.crate_details.version}}/{{this}}/{{../../metadata.target_name}}/" class="pure-menu-link">{{this}}</a></li>
  + <li class="pure-menu-item"><a href="/{{../../content.crate_details.name}}/{{../../content.crate_details.version}}/{{this}}/{{../../content.crate_details.target_name}}/" class="pure-menu-link">{{this}}</a></li>
  {{/each}}
  </ul>
  </li>
  