Update simple-statistics link (#997)

use direct link to github pages

README.md

@@ -41,7 +41,7 @@ See [danchitnis/webgl-plot](https://github.com/danchitnis/webgl-plot), [huww98/T
 
 In order to stay lean, fast and focused the following features will not be added:
 
-- No data parsing, aggregation, summation or statistical processing - just do it in advance. e.g. https://simplestatistics.org/, https://github.com/leeoniya/uDSV
+- No data parsing, aggregation, summation or statistical processing - just do it in advance. e.g. [simples-statistics](https://simple-statistics.github.io/), https://github.com/leeoniya/uDSV
 - No transitions or animations - they're always pure distractions.
 - No collision avoidance for axis tick labels, so may require manual tweaking of spacing metrics if label customization significiantly increases default label widths.
 - No stacked series: see ["Stacked Area Graphs Are Not Your Friend"](https://web.archive.org/web/20221208193656/https://everydayanalytics.ca/2014/08/stacked-area-graphs-are-not-your-friend.html) and a [horrific demo](https://leeoniya.github.io/uPlot/demos/stacked-series.html). While smooth spline interpolation is available, its use is strongly discouraged: [Your data is misrepresented!](http://www.vizwiz.com/2011/12/when-you-use-smoothed-line-chart-your.html). Both visualizations are terrible at accurately communicating information.