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/import-local/readme.md

@@ -0,0 +1,25 @@
+# import-local
+
+> Let a globally installed package use a locally installed version of itself if available
+
+Useful for CLI tools that want to defer to the user's locally installed version when available, but still work if it's not installed locally. For example, [AVA](https://avajs.dev) and [XO](https://github.com/xojs/xo) uses this method.
+
+## Install
+
+```sh
+npm install import-local
+```
+
+## Usage
+
+```js
+import importLocal from 'import-local';
+
+if (importLocal(import.meta.url)) {
+	console.log('Using local version of this package');
+} else {
+	// Code for both global and local version here…
+}
+```
+
+You can also pass in `__filename` when used in a CommonJS context.