Initial commit: Developer Tools MVP with visual editor

- Complete React app with 7 developer tools
- JSON Tool with visual structured editor
- Serialize Tool with visual structured editor
- URL, Base64, CSV/JSON, Beautifier, Diff tools
- Responsive navigation with dropdown menu
- Dark/light mode toggle
- Mobile-responsive design with sticky header
- All tools working with copy/paste functionality

node_modules/workbox-navigation-preload/enable.js

@@ -0,0 +1,41 @@
+/*
+  Copyright 2018 Google LLC
+
+  Use of this source code is governed by an MIT-style
+  license that can be found in the LICENSE file or at
+  https://opensource.org/licenses/MIT.
+*/
+import { logger } from 'workbox-core/_private/logger.js';
+import { isSupported } from './isSupported.js';
+import './_version.js';
+/**
+ * If the browser supports Navigation Preload, then this will enable it.
+ *
+ * @param {string} [headerValue] Optionally, allows developers to
+ * [override](https://developers.google.com/web/updates/2017/02/navigation-preload#changing_the_header)
+ * the value of the `Service-Worker-Navigation-Preload` header which will be
+ * sent to the server when making the navigation request.
+ *
+ * @memberof workbox-navigation-preload
+ */
+function enable(headerValue) {
+    if (isSupported()) {
+        self.addEventListener('activate', (event) => {
+            event.waitUntil(self.registration.navigationPreload.enable().then(() => {
+                // Defaults to Service-Worker-Navigation-Preload: true if not set.
+                if (headerValue) {
+                    void self.registration.navigationPreload.setHeaderValue(headerValue);
+                }
+                if (process.env.NODE_ENV !== 'production') {
+                    logger.log(`Navigation preload is enabled.`);
+                }
+            }));
+        });
+    }
+    else {
+        if (process.env.NODE_ENV !== 'production') {
+            logger.log(`Navigation preload is not supported in this browser.`);
+        }
+    }
+}
+export { enable };