Better Sad-Path Handling, Dependency Updates

Two main pieces of functionality were introduced:

• Improved error logging when a particular selector couldn't be found on a remote page.
• Automatically creation of a root index.html file if one doesn't already exist. It's possible that if people intend to fully develop an application against a remote page, they might not think to create a index.html file locally, even though it's required by Vite.

Additionally, the Vite dependency was bumped to v4, warranting a major version bump.