removed "participate" posts

we haven't posted a new study since 2021, so removing this section

index.html

@@ -103,14 +103,11 @@ <h2 class="f3">Courses</h2>
         in sorted_courses %}
 
         {% assign i = i | plus: 1 %}
-
         {% if i > 5 %} 
         {% assign break_loop = true %}  
         {% break %}     
         {% endif %}
 
-
-
         <li class="pb2">
           <a href="{{ course.url }}">{{ course.name }}</a>
           <span class="db f6 black-80"
@@ -129,15 +126,15 @@ <h2 class="f3">Courses</h2>
     </section>
   </div>
 
-  <div class="mv3 measure-wide">
+  <!-- <div class="mv3 measure-wide">
     <h2 class="f3 mt0">Participate</h2>
     <p class="lh-copy">
       Interested in sharing your expertise with us? Check out our ongoing
       research studies with visualization, machine learning, and data science
       practitioners!
     </p>
     <a class="link dim dib cta" href="/studies"> Learn More </a>
-  </div>
+  </div> -->
 
   <section class="pv3">
     <h2 class="f3">Recent Publications</h2>