docs(readme): add ArcGIS jimu-ui to in the wild section

ArcGIS bases it's UI library on reactstrap in their new Experience Builder product. Developers adding custom widgets to the map experience use and extend this library.

README.md

@@ -163,6 +163,7 @@ Organizations and projects using `reactstrap`
 - [DevExtreme React Chart](https://devexpress.github.io/devextreme-reactive/react/chart/) - A chart built on top of `reactstrap` that visualizes data using a variety of series types, including bar, line, area, scatter, pie, and more.
 - [reactstrap-scrollspy](https://github.com/keidrun/reactstrap-scrollspy/) - [demo](https://keidrun.github.io/reactstrap-scrollspy/)
 - [formstrap](https://github.com/pedox/formstrap/) - [demo](https://pedox.github.io/formstrap/) - Let your `reactstrap` input component integrate seamlessly using `Formik` 
+- [Jimu UI](https://developers.arcgis.com/experience-builder/api-reference/jimu-ui/) - [demo](https://developers.arcgis.com/experience-builder/storybook/?path=/story/welcome--page) - The UI library for [ArcGIS Experience Builder](https://developers.arcgis.com/experience-builder/)  mapping platform.
 
 Submit a PR to add to this list!