Idrees/enhancement/437 update join us page

[Idreesyaser]

📄 Pull Request Overview

Closes #437
Implements the fully responsive "Join Us" page based on the provided Figma design. This includes layout structure, styling, localization, dynamic content blocks, and automated tests.

🔧 Changes Made

1. Update Page: Update JoinUsPage with six dynamically generated content blocks (Discord, Contact, Feedback, etc.)

2. Block Component: Implemented a reusable component to render image, label, description, and one or more links.

3. Localization (i18n): Populated join-us.json for both fi and en locales with translated labels, descriptions, and links.

4. Assets: Added new image and icon assets for each block (stored under shared/assets/images and shared/assets/icons).

5. Styling: Created modular SCSS files for layout and individual blocks with support for responsiveness and accessibility.

6. Testing: Added unit tests for:

     Block rendering
   
     Page layout
   
     i18n generation function (makeJoinUsBlocks)
   

7. Storybook: Updated Storybook stories for the Block component and JoinUsPage for visual documentation.

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✅ Checklist Before Submission

• [✅] Functionality: Tested all blocks and responsive layout on Chrome and Firefox
• [✅] JSDoc: Added JSDoc to major helper functions and components
• [✅] Debugging: Removed all temporary console.log() statements
• [✅] Clean Code: Removed unused imports and commented-out code
• [✅] Tests: All related test suites pass (jest, @testing-library/react)
• [✅] Documentation: Documentation has been updated

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📝 Additional Information

Provide any additional context or information that reviewers may need to know:

• Dependencies: No new packages or dependencies added
• Known Issues: Current layout uses a manual marginTop workaround to handle sticky navbar. A more robust solution could be implemented later.