Background image storage

[github-actions[bot]]

Visit the preview URL for this PR (updated for commit 41e4e98):

https://truestrikevtt-25320--pr29-backgroundimagestora-3i23b3tj.web.app

_{(expires Sun, 07 Apr 2024 17:17:05 GMT)}

_{🔥 via Firebase Hosting GitHub Action 🌎}

_{Sign: e8a19a2bf24c7e198a214c44ce46911d31318a02}