flake: add nixf-diagnose to treefmt

Start off conservative ignoring more things. Handle the simple auto-fix
things initially.

Signed-off-by: Austin Horstman <khaneliman12@gmail.com>

flake.nix

@@ -57,6 +57,7 @@
               nixfmt
               deadnix
               keep-sorted
+              nixf-diagnose
             ];
             settings = pkgs.lib.importTOML ./treefmt.toml;
           }

treefmt.toml

@@ -10,6 +10,16 @@ command = "deadnix"
 options = [ "--edit", "--no-lambda-arg", "--no-lambda-pattern-names" ]
 includes = [ "*.nix" ]
 
+[formatter.nixf-diagnose]
+command = "nixf-diagnose"
+options = [
+  "--auto-fix",
+  "--ignore=sema-unused-def-lambda-witharg-formal",
+  "--ignore=sema-unused-def-lambda-noarg-formal",
+  "--ignore=sema-primop-overridden"
+]
+includes = [ "*.nix" ]
+
 [formatter.keep-sorted]
 command = "keep-sorted"
 includes = [ "*" ]