Add aliases for composer global

plugins/composer/composer.plugin.zsh

@@ -41,9 +41,12 @@ compdef _composer composer.phar
 alias c='composer'
 alias csu='composer self-update'
 alias cu='composer update'
+alias cr='composer require'
 alias ci='composer install'
 alias ccp='composer create-project'
 alias cdu='composer dump-autoload'
+alias cgu='composer global update'
+alias cgr='composer global require'
 
 # install composer in the current directory
 alias cget='curl -s https://getcomposer.org/installer | php'