message: Add Taxfix as adopters
diff: | [Prisjakt](https://www.prisjakt.nu) / [PriceSpy](https://pricespy.co.uk) | [@kennylindahl](https://github.com/kennylindahl) | Internal developer portal - Documentation, scaffolding, software catalog, TechRadar, Gitlab org data integration |
  | [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. |
  