chore: flake: add prettier to treefmt

Signed-off-by: Christoph Heiss <christoph@c8h4.io>

README.md

@@ -2,7 +2,7 @@
 
 ## Authors
 
-- Matthias Hofmarcher 
+- Matthias Hofmarcher
 - Moritz Kepplinger
 - Christoph Heiss
 - Mathias Trapl
@@ -16,5 +16,5 @@ Distributed under the AGPL-3.0-or-later license ([LICENSE](LICENSE) or https://s
 ### Contribution
 
 Unless you explicitly state otherwise, any contribution intentionally submitted
-for inclusion in the work by you shall be licensed by AGPL-3.0-or-later license 
+for inclusion in the work by you shall be licensed by AGPL-3.0-or-later license
 as above, without any additional terms or conditions.

flake.nix

@@ -25,6 +25,10 @@
             };
             statix.enable = true;
             deadnix.enable = true;
+            prettier = {
+              enable = true;
+              excludes = [ "backend/**" "frontend/openapi-generated/**" ];
+            };
           };
         };