Change Gradle depedency on site to be Kotlin friendly

Author: Jawnnypoo

Diff for: website/index.html

@@ -179,7 +179,7 @@ <h4>Maven</h4>
 &lt;/dependency></pre>
               <h4>Gradle</h4>
               <pre class="prettyprint">
-implementation 'com.squareup.retrofit2:retrofit:<span class="version pln"><em>(insert latest version)</em></span>'
+implementation("com.squareup.retrofit2:retrofit:<span class="version pln"><em>(insert latest version)</em></span>")
 </pre>
               <p>Retrofit requires at minimum Java 8+ or Android API 21+.</p>