- support for several command loaders to console application

- ability to declare event subscribers for console application events without dedicated event manager service
- PHP 8.1 support
- switch from PHPSpec to Kahlan (because of PHP 8.1)

- switch to Github Actions from Travis CI

- PHP 8.0 support (dependency update and test run)

- drop dependency from Zend Stdlib library (instead of migration to L…

…aminas Stdlib)

- possible fix for Packagist version sync

Badges and header markup fix