link checking for referenced field notes in essays

[njr2128]

to ensure all links referenced in essays to fieldnotes are resolving, go through the most recent link report run by Terry: https://github.com/cu-mkp/m-k-annotation-data/blob/master/qc/broken_links_report.txt
SUMMARY:

• HTML files checked: 134
• Total links/images found: 10513
• Unique remote URLs checked: 3808
• Unique local files checked: 0
• Total issues found: 146
  • Definitely broken: 146
  • Works in browser: 0
• Files with issues: 56

📊 Found issues in 56 files
💡 0 links work in browsers but fail automated checks