[GOOD FIRST ISSUE] Add real screenshots to README

Replace placeholder screenshots with actual images of the system.

Context:
README currently has placeholder sections for screenshots.

Suggested approach:
1. Boot the distro in a VM
2. Capture:
   - Desktop
   - Installer
3. Upload images to repo
4. Link them in README

Acceptance criteria:
- At least 2 screenshots added
- Images properly displayed in README

Files:
- README.md