Enable formatter for heex files

cv_gen/.formatter.exs

@@ -1,5 +1,5 @@
 # Used by "mix format"
 [
   plugins: [Phoenix.LiveView.HTMLFormatter],
-  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{heex,ex,exs}"]
 ]