Show current query in the search box

Dependencies

• [2] UICHT2PS Add a search feature
• [3] OEPUOUNB Using twitter bootstrap for more consistent looks for Hydra
• [*] QL55ECJ6 - adapted ui for hydra, more in line with nixos.org website

Change contents

• replacement in src/root/topbar.tt at line 192
  [2.2847]→[2.2847:2940](∅→∅)
  − <input name="query" type="text" class="search-query span2" placeholder="Search"></input>
  [2.2847]

  [2.2940]
  + <input name="query" type="text" class="search-query span2" placeholder="Search" [% HTML.attributes(value => c.req.params.query) %]></input>