Tweaked version, to make it look more like buienalarm and scale the y-axis a bit better

[spudje]

Sorry, I know I should learn github and make use of it's mechanisms. But don't have time for that now. So I'm just adding a tweaked version of the file here.

I included chart.js annotations to make it look more like buienalarm and used a different mechanism for the y-axis max, hoping it will scale better. I'm a very lazy and unskilled developer, so it won't look nice. But at least for me it works. Although I also still have to add the following style in the lovelace configuration:
.chartjs-render-monitor { height: 170px; }
buien-rain-card_spudje_20200812.zip