Fix broken medallion blog image paths causing build failure

[Copilot]

Description

Fixes the build error in the medallion architecture blog post by correcting case-sensitive local image paths so Docusaurus can resolve both images successfully.

Fixes # (issue)

Type of Change

• New feature (e.g., new page, component, or functionality)
• Bug fix (non-breaking change that fixes an issue)
• UI/UX improvement (design, layout, or styling updates)
• Performance optimization (e.g., code splitting, caching)
• Documentation update (README, contribution guidelines, etc.)
• Other (please specify):

Changes Made

• Updated blog/medallion-architecture/index.md image paths from ./img/... to ./Img/... to match the actual folder name.
• Kept all other blog content unchanged.

Dependencies

• No new dependencies.
• No version or configuration updates.

Checklist

• My code follows the style guidelines of this project.
• I have tested my changes across major browsers and devices
• My changes do not generate new console warnings or errors .
• I ran npm run build and attached screenshot(s) in this PR.
• This is already assigned Issue to me, not an unassigned issue.