Install the package with composer
composer req protonlabs/php-coding-standard --dev
To use it in your phpcs xml, add a rule pointing to the ruleset.xml
<?xml version="1.0"?>
<ruleset name="ProtonLabs PHP CodeSniffer Standard">
<!-- Proton Coding Standard – https://github.com/ProtonMail/php-coding-standard -->
<rule ref="vendor/protonlabs/php-coding-standard/Proton/ruleset.xml">
<!-- sniffs to exclude -->
<!-- <exclude name="SlevomatCodingStandard.PHP.UselessParentheses"/> -->
</rule>
<exclude-pattern>*/vendor/*</exclude-pattern>
</ruleset>