Feature request: (optionally) exit with error on bad doc comments

[jvillard]

When a bad doc comment is encountered, ocamlformat prints a warning, gives up on the comment, and exits with code 0 (success). It would be nice to have the option in ocamlformat to fail with an error code in that case, for instance to more easily keep a code base clean of errors in doc comments, especially as ocamlc won't complain about ill-formed doc comments either, although ocamldoc will.

Repro with ocamlformat version 0.14.1-13-g000da99:

$ echo '(** [ *)' | ocamlformat --impl -
Warning: Invalid documentation comment:
File "<standard input>", line 1, characters 6-6:
End of text is not allowed in '[...]' (code).
(** [ *)
$ echo $?
0

[gpetiot]

Maybe we could use a --strict option for ocamlformat that would treat all warnings as errors, not limited the the docstring warnings. Already discussed with @jberdine in #1388 although it was not really the source of the issue.