indie_external Indie External sites

Adds external Indie sites

https://docs.nextcloud.com/server/14/admin_manual/configuration_server/external_sites.html AGPL Joas Schilling customization integration tools https://github.com/nextcloud/external/raw/master/docs/admin-settings.png https://github.com/nextcloud/external/raw/master/docs/menu-and-settings-integration.png https://github.com/nextcloud/external/raw/master/docs/page-sample.png https://github.com/nextcloud/external https://github.com/nextcloud/external/issues https://github.com/nextcloud/external.git 3.9.1 IndieExternal OCA\IndieExternal\Settings\Section OCA\IndieExternal\Settings\Admin OCA\IndieExternal\Migration\CopyDefaultIcons OCA\IndieExternal\Migration\CopyDefaultIcons