Final move of registry into ecosystem section, and fix keyword search

[chalin]

• Contributes to Registry move-to-Ecosystem followup #2202
• Fully migrates the registry to be under /ecosystem
  • There are no more site pages or resources under /registry
• Redirects /registry/* to /ecosystem/registry
  • Query parameter are preserved in the redirect
• Tweaks the page design a bit:
  • New page section colors (see screenshot below)
• Ensures that the JSON data file is generated
• Ensure that the JS search uses updated paths, in particular to be able to access the JSON entries data
• Ran Prettifier on the main .md file

Preview:

• https://deploy-preview-2252--opentelemetry.netlify.app/ecosystem/registry
• https://deploy-preview-2252--opentelemetry.netlify.app/ecosystem/registry/?s=emf - shows that fuzzy search works
• https://deploy-preview-2252--opentelemetry.netlify.app/ecosystem/registry/?component=resource-detector
• https://deploy-preview-2252--opentelemetry.netlify.app/ecosystem/registry/index.json - the entries data file

Redirect tests:

• https://deploy-preview-2252--opentelemetry.netlify.app/registry
• https://deploy-preview-2252--opentelemetry.netlify.app/registry/?component=resource-detector

Screenshot: