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/babel-plugin-polyfill-regenerator/README.md

@@ -0,0 +1,28 @@
+# babel-plugin-polyfill-regenerator
+
+## Install
+
+Using npm:
+
+```sh
+npm install --save-dev babel-plugin-polyfill-regenerator
+```
+
+or using yarn:
+
+```sh
+yarn add babel-plugin-polyfill-regenerator --dev
+```
+
+## Usage
+
+Add this plugin to your Babel configuration:
+
+```json
+{
+  "plugins": [["polyfill-regenerator", { "method": "usage-global" }]]
+}
+```
+
+This package supports the `usage-pure`, `usage-global`, and `entry-global` methods.
+When `entry-global` is used, it replaces imports to `regenerator-runtime`.