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/workbox-webpack-plugin/build/lib/resolve-webpack-url.d.ts

@@ -0,0 +1,14 @@
+/**
+ * Resolves a url in the way that webpack would (with string concatenation)
+ *
+ * Use publicPath + filePath instead of url.resolve(publicPath, filePath) see:
+ * https://webpack.js.org/configuration/output/#output-publicpath
+ *
+ * @function resolveWebpackURL
+ * @param {string} publicPath The publicPath value from webpack's compilation.
+ * @param {Array<string>} paths File paths to join
+ * @return {string} Joined file path
+ *
+ * @private
+ */
+export declare function resolveWebpackURL(publicPath: string, ...paths: Array<string>): string;