Add Rocketseat icon, link

index.html

@@ -81,7 +81,11 @@
           
         <!-- Reddit -->
         <a class="button button-reddit" href="#"><img class="icon" src="icons/reddit.svg">Reddit</a>
-          <br>     
+          <br>   
+          
+         <!-- Rocketseat -->
+         <a class="button button-rocketseat" href="#"><img class="icon" src="icons/rocketseat.svg">Rocketseat</a>
+         <br>   
 
         <!-- Medium -->
         <a class="button button-medium" href="#"><img class="icon" src="icons/medium.svg">Medium</a>