Update changelog after new release 2.13.0

[mfn]

Summary

I've already updated the release page to contain this changelog -> https://github.com/barryvdh/laravel-ide-helper/releases/tag/v2.13.0

Type of change

• 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 not work as expected)
• This change requires a documentation update
• Misc. change (internal, infrastructure, maintenance, etc.)

Checklist

• Existing tests have been adapted and/or new tests have been added
• Add a CHANGELOG.md entry
• Update the README.md
• Code style has been fixed via composer fix-style

[barryvdh]

Thanks!