Regenerate MkDocs search index to remove stale :contentReference artifacts

[Copilot]

The linked review comment requested fixing only the stale citation-token artifacts that remained in generated search results. This update is scoped to that comment and ensures the search index reflects the current source Markdown content.

• Scope

  • Updated only docs/search/search_index.json (no source Markdown or unrelated generated pages changed).

• Search index content correction

  • Removed stale :contentReference[oaicite:…] fragments from contributor-guidelines search entries by regenerating the index from src_docs.
  • Preserved intended sentence text (e.g., leading clause in “According to the GitHub workshop slides, …”) as present in source docs.

• Before/after example (indexed text)

  // before
  "According to the GitHub workshop slides :contentReference[oaicite:1]{index=1}, repositories should typically contain:"
  
  // after
  "According to the GitHub workshop slides, repositories should typically contain:"

read only

[Dakout]

lgtm