Add a .formatter.exs to export the DSL

Author: ejpcmac

.formatter.exs

@@ -0,0 +1,15 @@
+locals_without_parens = [
+  aliases: 1,
+  argument: 2,
+  description: 1,
+  long_description: 1,
+  name: 1,
+  option: 2,
+  default_command: 1
+]
+
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"],
+  locals_without_parens: locals_without_parens,
+  export: [locals_without_parens: locals_without_parens]
+]