cross_toml: Fix docs URL

to point to the original repo instead of the fork for this PR.

src/cross_toml.rs

@@ -3,7 +3,7 @@
 //! For a detailed user documentation of the file and the contents please refer to the [docs in the
 //! repo][1].
 //!
-//! [1]: https://github.com/har7an/cross/blob/docs/restructure-docs-folder/docs/config_file.md
+//! [1]: https://github.com/cross-rs/cross/blob/main/docs/config_file.md
 
 use crate::docker::custom::PreBuild;
 use crate::docker::PossibleImage;