Added 404.html and config file for emojis :p

404.html

@@ -0,0 +1,10 @@
+---
+layout: main
+title: 404
+---
+<section>
+    <h2>Error 404</h2>
+    <p>
+        There is nothing there... maybe you want to go back to <a href="/">the index</a>
+    </p>
+</section>

_config.yml

@@ -0,0 +1,3 @@
+gems:
+    - jekyll-redirect-from
+    - jemoji

index.html

@@ -5,7 +5,12 @@ title: Index
 <section>
     <h2>Index</h2>
     <ul>
-        <li><a href="/bouncing/">A bouncing cube that jumps when you click on it</a></li>
+        <li>
+            <a href="/bouncing/">A bouncing cube that jumps when you click on it</a>
+            <p>
+                Jumps and bounce when you click on it :smiley:
+            </p>
+        </li>
         <li>
             <p>
             <a href="/multisphere/">Sphere with multi-resolution</a>