[RELEASE] Use PHP-CS-Fixer 3.x and new .php-cs-fixer.php config

This release supports PHP-CS-Fixer 3 and creates .php-cs-fixer.php now for configuration.

What's Changed

• [BUGFIX] Optimize search for autoloader by @gilbertsoft in #6
• [TASK] Synchronize rules with TYPO3 Core by @gilbertsoft in #7
• [TASK] Apply MD styles by @gilbertsoft in #8
• [BUGFIX] Search for autoloader by @gilbertsoft in #9
• [TASK] Upgrade to friendsofphp/php-cs-fixer 3.0 by @simonschaufi in #5

New Contributors

• @simonschaufi made their first contribution in #5
• @gilbertsoft made their first contribution in #6

Full Changelog: v0.3.0...v0.4.0