Rename documentation files to remove redundant prefixes (#589)

[praaatap]

Resolves #589

What this does

This PR performs a major structural cleanup of the content/docs/ directory by removing redundant folder prefixes from filenames (e.g., installation/installation-overview.md -> installation/overview.md).

Why this is high impact

• Hugo Migration Readiness: This satisfies a critical requirement for the Hugo migration project (Create index files of sections #588), moving the documentation into a clean hierarchical format.
• Improved Maintainability: Removes redundant naming that made the filesystem difficult to navigate.
• Zero-Risk Transformation: Since every markdown file already uses a static permalink in its frontmatter, the actual website URLs remain unchanged. No existing links will break.

Implementation Details

• Used git mv across the following directories to preserve full file history:
  • configuration/, couple-your-code/, installation/, running/, tooling/, dev-docs/, fundamentals/.
• Verified the Jekyll build locally to ensure integrity.

[MakisH]

Thank you for the contribution. We can only review this later, as this is work intended for the framework migration project and capacity right now is limited.

Not sure right now if this is a good idea.