Bug: Footer Social Media Links Are Not Functional

### Description
The social media icons (GitHub, Twitter, LinkedIn) in the footer section have empty `href` attributes.

Currently:
- Clicking on the icons does nothing.
- The links do not redirect to any external page.

This affects user experience and reduces the credibility of the application.

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### Expected Behavior
- Each social media icon should redirect to the respective profile or official page.
- Links should open in a new tab using `target="_blank"`.
- Add `rel="noopener noreferrer"` for security best practices.
- Optionally include `aria-label` for accessibility.

---

### Suggested Fix
Update the anchor tags with valid URLs and improve link attributes for better UX and security.

Example:
```html

Find the footer HTML file, likely named footer.html or within a layout file. Locate the anchor tags for the social media icons (GitHub, Twitter, LinkedIn). Replace the empty href attributes with the correct project URLs, and add target='_blank', rel='noopener noreferrer', and aria-label attributes. Test by clicking the icons to ensure they open the correct pages in a new tab.

Escrita pelo modelo de indexação a partir do texto da issue.