Remove fields [author, title, thumbnail] from _blog.yml

[mishig25]

Because those fields already exist inside individual posts. Example from ai-action-wh-2025.md:

---
title: "AI Policy @🤗: Response to the White House AI Action Plan RFI"
thumbnail: /blog/assets/151_policy_ntia_rfc/us_policy_thumbnail.png
authors:
- user: yjernite
- user: evijit
- user: irenesolaiman
---

# AI Policy @🤗: Response to the White House AI Action Plan RFI

python script that was used

#!/usr/bin/env python3
"""
Script to remove 'title', 'author', and 'thumbnail' fields from _blog.yml entries
while preserving formatting and blank lines.
"""

import re


def remove_fields_from_blog_yml(file_path):
    """
    Remove 'title', 'author', and 'thumbnail' fields from all entries in the blog YAML file.
    Preserves blank lines and formatting.
    
    Args:
        file_path: Path to the blog YAML file
    """
    # Fields to remove
    fields_to_remove = ["title", "author", "thumbnail"]
    
    # Read the file
    print(f"Reading {file_path}...")
    with open(file_path, "r", encoding="utf-8") as f:
        lines = f.readlines()
    
    # Process lines
    print("Processing lines...")
    new_lines = []
    removed_counts = {field: 0 for field in fields_to_remove}
    
    for line in lines:
        # Check if this line contains one of the fields to remove
        should_remove = False
        for field in fields_to_remove:
            # Match patterns like "  title:" or "  author:" or "  thumbnail:"
            if re.match(rf'^\s*{field}:\s*', line):
                should_remove = True
                removed_counts[field] += 1
                break
        
        # Keep the line if it's not one we want to remove
        if not should_remove:
            new_lines.append(line)
    
    # Write back to the file
    print(f"Writing changes back to {file_path}...")
    with open(file_path, "w", encoding="utf-8") as f:
        f.writelines(new_lines)
    
    # Print summary
    print("✓ Done!")
    print("\nSummary:")
    for field, count in removed_counts.items():
        print(f"  - Removed '{field}' from {count} entries")


if __name__ == "__main__":
    import sys
    
    files = sys.argv[1:] if len(sys.argv) > 1 else ["_blog.yml"]
    
    for file_path in files:
        remove_fields_from_blog_yml(file_path)
        print()

1. Removed fields from _blog.yml files ✓

• Removed title, author, and thumbnail from:
  • _blog.yml (648 entries)
  • zh/_blog.yml (218 entries)
  • fr/_blog.yml (3 entries)
• Preserved blank lines between entries for readability

2. Updated validation script ✓

• Removed title, author, thumbnail from _blog.yml schema validation
• Added frontmatter validation for all blog post .md files
• Validates required fields: title, thumbnail (with extension check), authors array
• Handles both Windows (\r\n) and Unix (\n) line endings
• Skips special files like README.md

3. Fixed markdown files ✓

• Fixed 19 files in root directory:
  • Added missing thumbnails (9 files)
  • Added placeholder authors (6 files)
  • Fixed invalid thumbnail extensions (2 files)
  • Removed leading whitespace (3 files)
• Fixed 2 files in zh/ directory:
  • Added missing authors and thumbnails

[julien-c]

lgtm on principle