Webby easter egg (api-platform#2196)

* Webby easter egg

* Fix style and name

* Fix review comments

Author: alanpoulain

src/Bridge/Symfony/Bundle/Resources/public/init-swagger-ui.js

@@ -1,6 +1,22 @@
 'use strict';
 
 window.onload = () => {
+    const webby = document.getElementsByClassName('webby')[0];
+    const web = document.getElementsByClassName('web')[0];
+    webby.classList.add('calm');
+    web.classList.add('calm');
+    webby.addEventListener('click', () => {
+        if (webby.classList.contains('frighten')) {
+            return;
+        }
+        webby.classList.replace('calm', 'frighten');
+        web.classList.replace('calm', 'frighten');
+        setTimeout(() => {
+            webby.classList.replace('frighten', 'calm');
+            web.classList.replace('frighten', 'calm');
+        }, 10000);
+    });
+
     const data = JSON.parse(document.getElementById('swagger-data').innerText);
     const ui = SwaggerUIBundle({
         spec: data.spec,