Add ENV PMA_UPLOADDIR and PMA_SAVEDIR to README.md

Author: Chris Proud

README.md

@@ -165,6 +165,8 @@ Set the variable ``PMA_ABSOLUTE_URI`` to the fully-qualified path (``https://pma
 * ``UPLOAD_LIMIT`` - if set, this option will override the default value for apache and php-fpm (format as `[0-9+](K,M,G)` default value is 2048K, this will change ``upload_max_filesize`` and ``post_max_size`` values)
 * ``HIDE_PHP_VERSION`` - if defined, this option will hide the PHP version (`expose_php = Off`). Set to any value (such as `HIDE_PHP_VERSION=true`).
 * ``APACHE_PORT`` - if defined, this option will change the default Apache port from `80` in case you want it to run on a different port like an unprivileged port.  Set to any port value (such as `APACHE_PORT=8090`)
+* ``PMA_UPLOADDIR`` - if defined, this option will set the name of the webserver directory where imported files can be saved to be available to import  ([$cfg['UploadDir']](https://docs.phpmyadmin.net/en/latest/config.html#cfg_UploadDir))
+* ``PMA_SAVEDIR`` - if defined, this option will set the name of the webserver directory where exported files will be saved ([$cfg['SaveDir']](https://docs.phpmyadmin.net/en/latest/config.html#cfg_SaveDir)) 
 
 For usage with Docker secrets, appending ``_FILE`` to the ``PMA_PASSWORD`` environment variable is allowed (it overrides ``PMA_PASSWORD`` if it is set):