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/webpack/lib/NoModeWarning.js

@@ -0,0 +1,22 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+const WebpackError = require("./WebpackError");
+
+module.exports = class NoModeWarning extends WebpackError {
+	constructor() {
+		super();
+
+		this.name = "NoModeWarning";
+		this.message =
+			"configuration\n" +
+			"The 'mode' option has not been set, webpack will fallback to 'production' for this value.\n" +
+			"Set 'mode' option to 'development' or 'production' to enable defaults for each environment.\n" +
+			"You can also set it to 'none' to disable any default behavior. " +
+			"Learn more: https://webpack.js.org/configuration/mode/";
+	}
+};