Improve README.md clarity for Web-dev-mini-projects

The current README lists projects and has basic contribution instructions, but it could be more beginner-friendly with clearer examples and visuals.

## Suggestions
1. **Add a sample project folder structure**
- Show how a typical project folder should look:
```
my-project/
├─ index.html
├─ style.css
├─ script.js
└─ README.md
```

2. **Include screenshots or GIFs**
- Visuals can help beginners understand folder structure and how projects appear in the list.

3. **Clarify contribution process briefly**
- Summarize steps from fork → add project → PR in one small section for easier reading.

Enhancing the README will make it more welcoming for first-time contributors and improve engagement.

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