Explain check_docs_formatted.py error message (#6125)

## Summary

This is an error message only change to lead an implementor of a new
rule that has an unformatted or invalid bad example to the
right code.

## Test Plan

n/a

scripts/check_docs_formatted.py

@@ -146,15 +146,19 @@ def format_file(
  if errors and not args.skip_errors and not error_known:
  for error in errors:
  rule_name = file.name.split(".")[0]
- print(f"Docs parse error for `{rule_name}` docs: {error}")
+ print(
+ f"Docs parse error for `{rule_name}` docs. Either fix or add to "
+ f"`KNOWN_PARSE_ERRORS`. {error}",
+ )
 
  return 2
 
  if contents != new_contents:
  rule_name = file.name.split(".")[0]
  print(
- f"Rule `{rule_name}` docs are not formatted. The example section "
- f"should be rewritten to:",
+ f"Rule `{rule_name}` docs are not formatted. Either format the rule or add "
+ f"to `KNOWN_FORMATTING_VIOLATIONS`. The example section should be "
+ f"rewritten to:",
  )
 
  # Add indentation so that snipped can be copied directly to docs