Why would I want something like that on an external resource like a wiki? What's wrong with having it right there in the source in a README.md?
Easily searchable on my machine with grep or ack or whatever you use. Many tools (such as github, many IDEs etc.) open it up with when you open up the project, including formatting it. If you really want, you can serve it up somewhere via HTTP. When something changes I can commit it right with the changes I'm making.
This works for developers but excludes large swathes of other stakeholders, some with huge amounts of business/process knowledge. MediaWiki supports WYSIWYG via VisualEditor, which increases usage from others (and has the benefit of making tables much more pleasant to work with).
I completely agree with you for documentation that is not developer centric. A wiki and a WYSIWYG editor is the way to go there. Though it is funny to see PMs and other people fight with say the Confluence editor (that's what I'm stuck with at the moment @work and they've recently effed up the Jira editors as well in favour of non-developers). It's abysmal and since they changed it to remove proper wiki syntax editing I can't even really fix things for them easily and have to use workarounds myself instead of teaching them a little bit of wiki markup syntax from time to time or using it myself to fix things. It's like MS Word and everyone learning all the workarounds of how to undo weird formatting or fix documents. What was wrong with LaTeX? :)
That is absolutely not what we're talking about here though. If a project manager really wants to set up a local dev env for whatever reason, they can be my guest but don't expect me to tailor our whole everything around them and not my developers.
I assume you're referring specifically to the coding style document rather than the host of things that a company should document. The advantage of having the coding style documented in a format that supports some kind of markup over a plain text file is to support syntax highlighting, searching/indexing, cross referencing other documents, including diagrams and a host of other features that plain text files lack support for.
You should not assume and I should have specified more clearly.
Our code style is also committed. As spotless configuration files, eslint configuration files etc. You can run these locally if you want to. Our CI/CD definitely runs them and fails the build if it doesn't pass. No exceptions.
The README.md I am speaking of is actually more than one README.md. We have more generalized ones dealing with "This is how to set up your dev env, so you can actually develop stuff", to more module specific ones like "this module is special from everything else in X, Y and Z".
Easily searchable on my machine with grep or ack or whatever you use. Many tools (such as github, many IDEs etc.) open it up with when you open up the project, including formatting it. If you really want, you can serve it up somewhere via HTTP. When something changes I can commit it right with the changes I'm making.