Add support for a desniff.yml configuration file

[bogdannbv]

Similar to what phpunit, phpcs, phpstan etc. are doing, a desniff.yml configuration file should be supported and automatically loaded if present and require CLI arguments only if they're not defined in the config file.

The file should support all the existing CLI arguments.

We should provide a default configuration file that contains the default values for all the existing CLI arguments:

• <env-file> - .env.example
• <paths> - ./config
• --fail-code - 1
• --warn-with-default - false
• --ansi - true
• --quiet - false

The default configuration file should be generated using an init command:

./vendor/bin/desniff init

The configuration file should be automatically loaded if present but also the user should be able to provide it using an argument (-c | --config and --fail-code should become -f:

./vendor/bin/desniff -c desniff.ci.yml