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/toPath.js

@@ -0,0 +1,12 @@
+define(['./isArray', './underscore'], function (isArray, underscore) {
+
+  // Normalize a (deep) property `path` to array.
+  // Like `_.iteratee`, this function can be customized.
+  function toPath(path) {
+    return isArray(path) ? path : [path];
+  }
+  underscore.toPath = toPath;
+
+  return toPath;
+
+});