Add ocamlformat-mlx for .mlx files

[davesnx]

Small PR to format mlx files with ocamlformat-mlx.

In mlx we encourage dune fmt via dune dialects, but the lsp runs those formatters outside of dune.

(dialect
 (name mlx)
 (implementation
  (extension mlx)
  (merlin_reader mlx)
  (format
   (run ocamlformat-mlx %{input-file}))
  (preprocess
   (run mlx-pp %{input-file}))))

[andreypopp]

Suggested change

	| Intf -> [ re; ml; mly; mll ]
	| Intf -> [ re; ml; mly; mll; mlx ]

as we want to be able to switch to .mlx from .mli if it is present

[voodoos]

But here we are matching on an "Mlx Intf", which is not an mli file, right ? I am not sure that case happens at all. But nothing really bad could happen from having too many of such rules...

[andreypopp]

looking at the surrounding code, I thought the kind belongs to the origin, so we are on interface file and want to switch to the implementation, which can be .re, .ml, .mly, mll, and now .mlx

[andreypopp]

not clear what's the TODO about

[voodoos]

@davesnx I am not familiar with ocamlformat-mlx, but overall this looks correct.

However the CI is failing with a non-exhaustive pattern matching error, could you fix that ?

[davesnx]

Embarrassing, I would push this forward. Thanks for the review @voodoos.

I wanted to test this PR manually before merging as well, is it as easy as pinning to ensure everything works or do I need something else?

[voodoos]

I wanted to test this PR manually before merging as well, is it as easy as pinning to ensure everything works or do I need something else?

I would expect so, please report if it doesn't :-)