Add OCaml

[whitequark]

OCaml uses stalebot and I ended up in a rather bitter conflict over that (which I won't link to, but it's easy to find if you care).

E.g.:

• Add functions to help printing Uchar.t values ocaml/ocaml#11999 (comment)
• Remaining issues in the OCaml 5 systhread implementation ocaml/ocaml#12399 (comment)

The second one is particularly cursed since the comment says:

I am unsubscribing from this issue, notably to avoid being pinged by the stale bot in case nothing is done (just so you know in case you need to ping me).

Really making your case for you!