Fix dead link to Cargo.toml in documentation

../../Cargo.toml resolves to https://rust-analyzer.github.io/Cargo.toml, which is an invalid link

Author: donni-h

docs/book/src/contributing/style.md

@@ -101,7 +101,7 @@ Including a description and GIF suitable for the changelog means less work for t
 
 ## Clippy
 
-We use Clippy to improve the code, but if some lints annoy you, allow them in the [Cargo.toml](../../Cargo.toml) [workspace.lints.clippy] section.
+We use Clippy to improve the code, but if some lints annoy you, allow them in the [Cargo.toml](https://github.com/rust-lang/rust-analyzer/blob/master/Cargo.toml) [workspace.lints.clippy] section.
 
 # Code