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/underscore/amd/defer.js

@@ -0,0 +1,9 @@
+define(['./underscore', './partial', './delay'], function (underscore, partial, delay) {
+
+	// Defers a function, scheduling it to run after the current call stack has
+	// cleared.
+	var defer = partial(delay, underscore, 1);
+
+	return defer;
+
+});