doc_markdown should ignore things which just contain acronyms

[Manishearth]

Instead of needing to manually whitelist, we should ignore things like DirectX and OpenGL. For something to be camel case, it should have at least two camelcase words in it, each which have at least one lowercase letter.

[gnzlbg]

I have a crate where this warning is extremely annoying: https://github.com/gnzlbg/bitintr

The documentation is full of acronyms like x86_64, ARMv7, AMD, ... this warning trips up in extremely many files.

IMO the correct fix should be to only suggest putting something into `` when it is actually a type.

[mcarton]

@gnzlbg

when it is actually a type.

Or a function, or a variant, or a mod, or… A this must be from any crate the project depends on.

Do you know that this lint is configurable?

[cauebs]

@Manishearth That will still end up linting 15/39 of the current whitelist ("GitHub", "GitLab", "ClojureScript", "CoffeeScript", "JavaScript", "PureScript", "TypeScript", "NaNs", "OpenStreetMap", "TensorFlow", "TrueType", "LaTeX", "BibTeX", "BibLaTeX", "CamelCase"). It might be a step in the right direction, but what does it achieve effectively?

I could give this one a crack but I think first we have to figure out a decent heuristic. The current rule is not great, specially that it ignores things that end in 's' as if they're plural (what about DeviceBus?). I'm not keen on complicating this lint a lot more, though.

The idea of checking if the word is an identifier present in the crate (or module) or its dependencies sounds better. Is it feasible?

[Kinrany]

Perhaps PascalCase words should have their own separate lint. It feels sufficiently more pedantic and less consequential than other parts of doc_markdown that actually protect Markdown rendering from being broken.