Add text color classes

web/app/templates/playground/index.html.j2

@@ -131,7 +131,7 @@
   <div class="card">
     <div class="card-content">
       <a class="btn-floating btn-large hoverable left" style="margin-right: 15px;">
-        <i class="material-icons service" data-service="corpus_analysis"></i>
+        <i class="material-icons service" data-service="corpus-analysis"></i>
       </a>
       <span class="card-title">Corpus analysis</span>
       <i>Create as many text corpora as you want. It makes use of CQP Query Language, which allows for complex search requests with the aid of metadata and NLP tags.</i>