Things to do before release

These are the things that need to be done for **Release 1.0**

- [ ] Place background image in new `images` folder
- [ ] Modify speed of game
- [ ] Modify brick colors
- [ ] Maybe more ❓ ❓ ❓ ❓ ❓

Start by reviewing the repository layout and the open Release 1.0 checklist, then locate the game's background image assets and the settings controlling speed and brick colors. Add the background image in a new images folder and complete the requested visual and speed changes; clarify the open-ended “Maybe more” item before considering the release checklist complete.

索引モデルが issue の本文から書いたものです。