Dutch translation added

[GH2user]

Hi Jeroen, Great work on this sensor! I have added a dutch translation and will promote this one on a dutch HomeAssistant foruim. I know the first question you will get is can we have the time of the max/min as an attribute to the sensor.

So should I create a request for this or is it something hardly possible (translating I can do but coding at that level is something diffferent).

rgds, nico