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/is-regexp/readme.md

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+# is-regexp [![Build Status](https://travis-ci.org/sindresorhus/is-regexp.svg?branch=master)](https://travis-ci.org/sindresorhus/is-regexp)
+
+> Check whether a variable is a regular expression
+
+
+## Install
+
+```sh
+$ npm install --save is-regexp
+```
+
+
+## Usage
+
+```js
+var isRegexp = require('is-regexp');
+
+isRegexp('unicorn');
+//=> false
+
+isRegexp(/unicorn/);
+//=> true
+
+isRegexp(new RegExp('unicorn'));
+//=> true
+```
+
+
+## License
+
+MIT © [Sindre Sorhus](http://sindresorhus.com)