fix: hello world template

jina/resources/helloworld.html

@@ -22,7 +22,7 @@
     <h2 style="color: #1E6E73">What just happened?</h2>
     <span>This is Jina's <pre style="display: inline;">hello-world</pre>, end-to-endly. It downloads Fashion-MNIST dataset and indexes 60,000 images via Jina search framework. The index is stored into multiple <i>shards</i>. We then randomly sample unseen images as <i>Queries</i>, ask Jina to retrieve relevant results. Below is Jina's retrievals, where the left-most column is query image. </span>
     <br>
-    <span>Intrigued? Learn more about Jina and checkout our Github!</span>
+    <span>Intrigued? Learn more about Jina and <a href="https://opensource.jina.ai">checkout our Github!</a></span>
 </div>
 <hr style="border: 1px dashed #009999;">