Documentation: Add list of supported tools and how to ensure the checks are being properly generated

[boesing]

Feature Request

Q	A
New Feature	no
RFC	no
BC Break	no

Summary

This component supports some tools for CI pipeline, such as:

• PHPCodeSniffer
• Psalm
• PHPUnit
• PHP-CS-Fixer
• etc.

(List of supported tools can be found in this file)

At least for one tool (PHP-CS-Fixer), we require a project to have a composer-require-checker.json configuration file available. This is because the tool does not have a default filename for this and thus, we decided to go with this filename.

For infection, we do support the static-analysis tool from Roave as well, but do not list it anywhere in the README or docs.

So this Issue is to ensure we do improve the documentation of this github action so that every1 who wants to use this CI Pipeline is aware of how to configure the project.