Add rustdoc --check to rustdoc's docs

[edmorley]

Support for rustdoc --check was added in #78984, and it can be seen in the output from rustdoc --help:

$ rustdoc --help
...
        --check         Run rustdoc checks

However there is no mention of it on:
https://doc.rust-lang.org/rustdoc/command-line-arguments.html

Which is built from:
https://github.com/rust-lang/rust/blob/e4b1d5841494d6eb7f4944c91a057e16b0f0a9ea/src/doc/rustdoc/src/command-line-arguments.md

[GuillaumeGomez]

Thanks for opening this issue! Want to send a PR for it maybe? :)

[edmorley]

Comparing rustdoc --help and that docs page, I see a few other inconsistencies. It seems that having the page be auto-generated might be more sustainable longer term?

I can open a PR for this instance in the meantime, however.

[edmorley]

Hmm all of these are missing too:

    -A, --allow LINT    Set lint allowed
    -W, --warn LINT     Set lint warnings
        --force-warn LINT
                        Set lint force-warn
    -D, --deny LINT     Set lint denied
    -F, --forbid LINT   Set lint forbidden

I think I might skip a PR for now, since really the whole doc needs careful review.

[GuillaumeGomez]

Comparing rustdoc --help and that docs page, I see a few other inconsistencies. It seems that having the page be auto-generated might be more sustainable longer term?

I'm not sure auto-generated would work nicely... The best would maybe to add a check for it like we do for a few other things.

I can open a PR for this instance in the meantime, however.

That would be very appreciated!

[GuillaumeGomez]

Fixed in #94015.