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/semver/ranges/valid.js

@@ -0,0 +1,13 @@
+'use strict'
+
+const Range = require('../classes/range')
+const validRange = (range, options) => {
+  try {
+    // Return '*' instead of '' so that truthiness works.
+    // This will throw if it's invalid anyway
+    return new Range(range, options).range || '*'
+  } catch (er) {
+    return null
+  }
+}
+module.exports = validRange