Document .php-version support
Document .php-version support

nsg/dokku-buildpack-picocms,pierredup/packager-buildpack-php,CHH/heroku-buildpack-php,bobmaerten/dokku-buildpack-php,stof/heroku-buildpack-php,jstacoder/heroku-buildpack-php-1,nsg/dokku-buildpack-picocms,Jonatasmz/php-buildpack,CHH/heroku-buildpack-php,penciu/apache,ryosuzuki/php-buildpack,bobmaerten/dokku-buildpack-php,OKAMca/heroku-buildpack-php,pierredup/packager-buildpack-php,OKAMca/heroku-buildpack-php,penciu/apache,Scalingo/php-buildpack,jstacoder/heroku-buildpack-php-1,penciu/apache,OKAMca/heroku-buildpack-php,stof/heroku-buildpack-php,mraymond/heroku-buildpack-php,AlphaStaxLLC/heroku-buildpack-php-custom,Scalingo/php-buildpack,stof/heroku-buildpack-php,AlphaStaxLLC/heroku-buildpack-php-custom,AlphaStaxLLC/heroku-buildpack-php-custom,mraymond/heroku-buildpack-php,Jonatasmz/php-buildpack,cachethq/cachet-buildpack,CHH/heroku-buildpack-php,ryosuzuki/php-buildpack,Scalingo/php-buildpack