Make sure you've saved manifest.json and popup.html, head back to chrome://extensions/, click the expand icon next to the Hello World extension in the Extension list, then click the Reload link ...

Chrome extensions are built primarily with HTML and JavaScript. This means that Web developers can use their existing skills and dive into Chrome augmentation without having to learn a completely ...

Learn how to export Google Chrome Bookmarks to HTML format on Windows. You can also import bookmarks to Chrome without a Google account.