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/object-inspect/test/holes.js

@@ -0,0 +1,15 @@
+var test = require('tape');
+var inspect = require('../');
+
+var xs = ['a', 'b'];
+xs[5] = 'f';
+xs[7] = 'j';
+xs[8] = 'k';
+
+test('holes', function (t) {
+    t.plan(1);
+    t.equal(
+        inspect(xs),
+        "[ 'a', 'b', , , , 'f', , 'j', 'k' ]"
+    );
+});