Extend zz-docker with process manager config (#1519)

Author: melroy89

docker/php/php-fpm.d/zz-docker.conf

@@ -4,5 +4,13 @@ process_control_timeout = 20
 
 [www]
 listen = 9000
+
+; process manager
+pm = dynamic
+pm.max_children = 100
+pm.start_servers = 12
+pm.min_spare_servers = 5
+pm.max_spare_servers = 15
+
 ping.path = /ping
 ping.response = OK