Adding one laser to dsminer

The Deep Space Miner has got the word "Miner" in its name. In addition to this it has got a lot of cargo space and a cargoscoop. It is the ideal mining vehicle - but without a mining laser it doesn't make sense. So I added one line to add one laser slot. Only one slot because it is enough for mining but not enough for having a really strong fighter. And the miner shouldn't be used as a fighter.