Add transparent badge.

source/core-team/index.html

@@ -338,7 +338,7 @@ footer: true
       </div>
       <div class="col-sm-9 col-md-9">
         <h2 class="title">Jeroen van Baarsen</h2>
-        <img src="/images/merge_marshal/mm_badge_pgd_250.png">
+        <img src="/images/merge_marshal/mm_badge_st.png">
       </div>
     </div>
     <div class="row">
@@ -368,7 +368,7 @@ footer: true
       </div>
       <div class="col-sm-9 col-md-9">
         <h2 class="title">Drew Blessing</h2>
-        <img src="/images/merge_marshal/mm_badge_pgd_250.png">
+        <img src="/images/merge_marshal/mm_badge_st.png">
       </div>
     </div>
     <div class="row">