Add charjs-plugin-autocolors (chartjs#37)

* Add charjs-plugin-autocolors

* Remove Chart.js from description

Author: kurkle

README.md

@@ -39,6 +39,7 @@ A curated list of awesome things related to [Chart.js](https://www.chartjs.org)
   Name | Description | Chart.js v2 | Chart.js v3
   ---- | ----------- | :--: | :--:
   [annotation](https://github.com/chartjs/chartjs-plugin-annotation) | Draws lines and boxes on the chart area | ✔ | ✔
+  [autocolors](https://github.com/kurkle/chartjs-plugin-autocolors) | Automatic color generation | | ✔
   [colorschemes](https://github.com/nagix/chartjs-plugin-colorschemes) | Enables automatic coloring using predefined color schemes | ✔ | ✔
   [crosshair](https://github.com/abelheinsbroek/chartjs-plugin-crosshair) | Adds a data crosshair to line and scatter charts | ✔ | ✔
   [datalabels](https://github.com/chartjs/chartjs-plugin-datalabels) | Displays labels on data for any type of charts | ✔ | ✔