v0.3.0 (Up php to 8.1)

(#1) Changes:

• Up php to 8.1
• Change mougrim/php-logger to own psr/log compatible logger
• Add type declaring and hints everywhere
• Add declare(strict_types=1) to all php-files
• Pass parameters to constructor instead of using setters
• Use psr-4 autoload instead of psr-0
• Use readonly properties instead of getters
• Add badges to README.md
• Chane placeholders in param values using param values