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-precaching/addRoute.d.ts

@@ -0,0 +1,19 @@
+import { PrecacheRouteOptions } from './_types.js';
+import './_version.js';
+/**
+ * Add a `fetch` listener to the service worker that will
+ * respond to
+ * [network requests]{@link https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API/Using_Service_Workers#Custom_responses_to_requests}
+ * with precached assets.
+ *
+ * Requests for assets that aren't precached, the `FetchEvent` will not be
+ * responded to, allowing the event to fall through to other `fetch` event
+ * listeners.
+ *
+ * @param {Object} [options] See the {@link workbox-precaching.PrecacheRoute}
+ * options.
+ *
+ * @memberof workbox-precaching
+ */
+declare function addRoute(options?: PrecacheRouteOptions): void;
+export { addRoute };