message: Add Busuu as Adopters
diff: | [Powerspike](https://powerspike.tv/) | [@trelore](https://github.com/trelore) | Developer portal for documentation of core libraries and repositories. |
  | [2U](https://2u.com) | [Andrew Thal](https://github.com/athal7) | Development team home-base, promoting service discoverability, resource dependencies, and tech radar |
  | [Taxfix](https://taxfix.de/) | [Sami Ur Rehman](https://github.com/samiurrehman92) | Developer's portal with software catalog at it's core. Hosts API Specs, Tech Docs, Tech Radar and some custom plugins. |
  +| [Busuu](https://busuu.com/) | [Adam Tester](https://github.com/adamtester) | Developer portal with service catalog, API docs, Event docs, service templating, and cost insights. |
  