add composer install instructions to readme.md .

[willgopublic]

Perhaps composer install instructions can be added to the readme.md .

composer require --dev --prefer-dist -- wcm/git-php-hooks

wcm/git-php-hooks suggests installing wcm/git-php-hooks-library (A convenient library of pre made hooks and tasks.)

composer require --dev --prefer-dist -- wcm/git-php-hooks-library

[franz-josef-kaiser]

@willgopublic Has my +1. Would you like to file a PR?