manual: remove suggestion of rust-project.json example

[cbiffle]

The manual has been linking to the repo

https://github.com/rust-analyzer/rust-project.json-example/tree/master

This repo does not contain a rust-project.json, does not appear to have ever contained a rust-project.json, and my bug report about this has gone untouched: rust-analyzer/rust-project.json-example#4

Since I can't figure out an example, this commit removes the link pending better documentation.

[lnicola]

That repo has an example of the third option, just like it was pointed out in rust-analyzer/rust-project.json-example#4 (comment).

[cbiffle]

That seems like an example of how to write a vscode configuration file. Is this section intended to be vscode-specific? Perhaps it would be worth telling readers to look in the .vscode directory (which I skipped, not being a vscode user, looking for a rust-project.json file that doesn't exist)?

[lnicola]

Specify "rust-analyzer.linkedProjects": [ { "roots": […​], "crates": […​] }] inline.

It's literally that. It's not Code-specific, every LSP client will support changing the server settings. But the syntax depends on the client, unfortunately.

[Veykril]

I wonder if we can make a simple CLI thing for r-a that turns a cargo project into a rust-project.json file. That feels like a nice way to help people figure out the format 🤔 Also let's archive that repo, it showing it in the vscode settings isn't really helpful imo.

[Veykril]

Also there is https://json.schemastore.org/rust-project.json which might help (I dont remember if we have docs for rust-project.json)

[lnicola]

We have https://rust-analyzer.github.io/manual.html#non-cargo-based-projects, which may or may not be up-to-date.

[Veykril]

I'll merge this, I am not too fond of that example, especially because that third option isn't meant to be written manually anyways.
@bors r+

[bors]

📌 Commit 898d466 has been approved by Veykril

It is now in the queue for this repository.

[bors]

⌛ Testing commit 898d466 with merge 1e61ed7...

[bors]

☀️ Test successful - checks-actions
Approved by: Veykril
Pushing 1e61ed7 to master...