Fix 404 link: /documentation/references/artifacts/gRPC-conventions

[yada]

Broken link (404)

• URL: https://microcks.io/documentation/references/artifacts/gRPC-conventions
• HTTP status: 404
• Found on: https://microcks.io/documentation/references/artifacts/
• Also found on: https://microcks.io/documentation/references/artifacts

What to do

• Update the source page(s) to point to the correct/current gRPC conventions documentation.
• Ensure the final destination is a valid Microcks docs page.

Help needed

Not sure which page should replace it? Comment here with your best guess and we’ll confirm.