add missing Dockerfile

Dockerfile

@@ -0,0 +1,22 @@
+FROM nextcloud:30
+
+ARG APP_NAME=app_template
+ENV NEXTCLOUD_UPDATE=1
+ENV NEXTCLOUD_ADMIN_USER=$APP_NAME
+ENV NEXTCLOUD_ADMIN_PASSWORD=$APP_NAME
+ENV NEXTCLOUD_INIT_HTACCESS=1
+ENV SQLITE_DATABASE=$APP_NAME
+
+RUN apt-get update && \
+    apt-get install -y nodejs npm sqlite3 && \
+    rm -f /usr/local/etc/php/conf.d/opcache-recommended.ini && \
+    /entrypoint.sh true
+
+USER www-data
+
+COPY --chown=www-data:www-data . apps/$APP_NAME
+RUN cd apps/$APP_NAME && make build && cd - && \
+    php occ app:enable $APP_NAME && \
+    php occ config:system:set debug --value=true
+
+USER root