feat: Add screenshots and add demo video

This commit adds screenshots and adds a demo video.

Changes:

-   Added the following screenshot files in the `screenshots` directory: `1.png`, `2.png`, `3.png`, `4.png`, `5.png`, `6.png`, `7.png`, `8.png`.
- Added a new `Demo Video.mp4` in `demo Video` folder

Author: CGreenP