Manifest V3 Update

This update brings about updating the Manifest to V3. This brings an update to prevent V3 from running in the background, which V2 allowed. This security update actually helps in making this theme even more lightweight and safer.

I may upload this theme to the Google Chrome extensions store, but in order to do so, I'll need to pay $5 USD, and while small, I don't know if it'll be worth it, as I may never make back my money on this, making it feel more like a lost cause and failure.