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-build/build/lib/escape-regexp.js

@@ -0,0 +1,15 @@
+"use strict";
+/*
+  Copyright 2019 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.
+*/
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.escapeRegExp = void 0;
+// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
+function escapeRegExp(str) {
+    return str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}
+exports.escapeRegExp = escapeRegExp;