Add local sitepackage to composer based installation

sitepackage_composer

# Add folder local_extension to document root and place sitepackage inside of it
# then add the repository to composer.json calling

composer config repositories.sitepackage path local_extensions/*

# then install the sitepackage in composer
composer req pixelink/sitepackage

# thats it all required extensions are loaded and it's autoloaded if therer are any extensions hooks or similar