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/prompts/dist/dateparts/meridiem.js

@@ -0,0 +1,25 @@
+'use strict';
+
+const DatePart = require('./datepart');
+
+class Meridiem extends DatePart {
+  constructor(opts = {}) {
+    super(opts);
+  }
+
+  up() {
+    this.date.setHours((this.date.getHours() + 12) % 24);
+  }
+
+  down() {
+    this.up();
+  }
+
+  toString() {
+    let meridiem = this.date.getHours() > 12 ? 'pm' : 'am';
+    return /\A/.test(this.token) ? meridiem.toUpperCase() : meridiem;
+  }
+
+}
+
+module.exports = Meridiem;