Add message in search results for pull requests and twitter contact

_layouts/search.html

@@ -13,6 +13,9 @@ <h1>Search results</h1>
   <!-- Pagination widget will appear here -->
 </div>
 <div id="search-footer">
+  <p>If you know what this expression means, you can add it by sending us a
+  <a href="https://github.com/tupilabs/speaklikeabrazilian.com/issues/new?assignees=kinow&labels=expressions&projects=&template=add-or-update-an-expression.md&title=Add+expression%3A+">pull request</a>,
+  or contact us via <a href="https://www.twitter.com/speaklikeabr">Twitter</a>.</p>
   <a href="https://www.algolia.com/">
     <img src="{{ '/assets/images/search-by-algolia-light-background.png' | relative_url }}" alt="Search by Algolia">
   </a>