Fix some broken rustc-dev-guide links

CONTRIBUTING.md

@@ -92,4 +92,4 @@ of the terminology used in chalk.
 ### Trait solving in rustc-dev-guide
 The rustc-dev-guide describes [new-style trait solving][trait-solving], which is slowly replacing the old trait resolution.
 
-[trait-solving]: https://rustc-dev-guide.rust-lang.org/traits/index.html
+[trait-solving]: https://rustc-dev-guide.rust-lang.org/traits/chalk.html

README.md

@@ -11,7 +11,9 @@ See the [Chalk book](https://rust-lang.github.io/chalk/book/) for more informati
 
 ## FAQ
 
-**How does chalk relate to rustc?** The plan is to have rustc use the `chalk-engine` crate (in this repo), which defines chalk's solver. The rest of chalk can then be considered an elaborate unit testing harness. For more details, see [the Traits chapter of the rustc-dev-guide](https://rustc-dev-guide.rust-lang.org/traits/index.html).
+**How does chalk relate to rustc?** The plan is to have rustc use the `chalk-engine` crate (in this repo), which defines
+chalk's solver. The rest of chalk can then be considered an elaborate unit testing harness. For more details, see
+[this chapter of the rustc-dev-guide](https://rustc-dev-guide.rust-lang.org/traits/chalk.html).
 
 **Where does the name come from?** `chalk` is named after [Chalkidiki], the area where [Aristotle] was
 born. Since Prolog is a logic programming language, this seemed a

chalk-engine/src/context.rs

@@ -44,9 +44,9 @@ pub trait Context: Clone + Debug {
 
     /// A canonicalized `GoalInEnvironment` -- that is, one where all
     /// free inference variables have been bound into the canonical
-    /// binder. See [the rustc-dev-guide] for more information.
+    /// binder. See [the chalk book] for more information.
     ///
-    /// [the rustc-dev-guide]: https://rustc-dev-guide.rust-lang.org/traits/canonicalization.html
+    /// [the chalk book]: https://rust-lang.github.io/chalk/book/canonical_queries/canonicalization.html
     type CanonicalGoalInEnvironment: Debug;
 
     /// A u-canonicalized `GoalInEnvironment` -- this is one where the

chalk-engine/src/lib.rs

@@ -1,8 +1,8 @@
 //! An alternative solver based around the SLG algorithm, which
 //! implements the well-formed semantics. For an overview of how the solver
-//! works, see [The On-Demand SLG Solver][guide] in the rustc-dev-guide.
+//! works, see [The On-Demand SLG Solver][guide] in the chalk book.
 //!
-//! [guide]: https://rustc-dev-guide.rust-lang.org/traits/slg.html
+//! [guide]: https://rust-lang.github.io/chalk/book/engine/slg.html
 //!
 //! This algorithm is very closed based on the description found in the
 //! following paper, which I will refer to in the comments as EWFS: