Add required parameter examples and linter rule

[Jython1415]

This commit implements the require-parameter-examples linter rule to ensure all formula parameters have non-empty example values.

Changes:

• Add RequireParameterExamplesRule class to scripts/lint_formulas.py

  • Validates all parameters have non-empty 'example' fields
  • Supports edge cases: zero values, falsy values, quoted strings, BLANK()
  • Registered in FormulaLinter (4 rules now)

• Add comprehensive test suite (16 test cases) to tests/test_linter.py

  • TestRequireParameterExamplesRule with positive and negative cases
  • Test edge cases and error messages
  • Updated rule count assertion (3 -> 4 rules)

• Fix NONERRORSTO formula in formulas/nonerrorsto.yaml

  • Changed replacement parameter example from empty string to '""'
  • Represents the double-quoted empty string example

• Update documentation

  • CLAUDE.md: Example YAML, linter rules list, formula development best practices
  • tests/CLAUDE.md: Parameter examples rule documentation

• Regenerate README.md

  • NONERRORSTO replacement parameter now shows '""' as example

All tests pass (180 tests), linter validates all 33 formulas successfully.