remove aulas collection in favor of using plugin

_includes/Pages/aulas.html

@@ -3,15 +3,14 @@
         <h1>Aulas</h1>
     </div>
     <div class="content">
-        {% assign aulas = site.aulas | sort: 'date' | reverse %}
+        {% assign aulas = site.data.aulas | sort: 'date' | reverse %}
         {% assign max_aulas = 3 %}
 
         {% for aula in aulas %}
-        {% assign nome = aula.name | replace: ".md","" %}
         <div class="box">
             <div class="box-top">
                 <figure>
-                    <img src="{{ site.baseurl }}/assets/thumbs/{{ nome }}.jpg">
+                    <img src="{{ site.baseurl }}/assets/thumbs/{{ aula.title }}.jpg">
                 </figure>
             </div>
 
@@ -23,4 +22,4 @@
         
         {% endfor %}
     </div>
-</div>
+</div>