feat(rules): add max line length to body/footer

[Fetz]

Description

Allow to add max line length rules to both body and footer

Motivation and Context

fix: https://github.com/marionebl/commitlint/issues/208
enable: https://github.com/marionebl/commitlint/issues/303

Usage examples

// commitlint.config.js
module.exports = {
 rules: {
    'body-max-line-length': [1, 'always', 50],
    'footer-max-line-length': [1, 'always', 50],
  }
};

How Has This Been Tested?

• I didn't test manually yet
• I assumed that body and footer will not have initial/end empty lines, if is need to handle than I can add https://www.npmjs.com/package/trim-off-newlines to handle it

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[kosssi]

@Fetz thanks for your contribution, I search exactly this feature @macklinu can you integrate it ?

[marionebl]

Thanks!