Address review comments.

Co-Authored-By: Who? Me?! <mark-i-m@users.noreply.github.com>

src/SUMMARY.md

@@ -77,10 +77,10 @@
         - [Caching subtleties](./traits/caching.md)
         - [Specialization](./traits/specialization.md)
         - [Chalk-based trait solving](./traits/chalk.md)
-        - [Lowering to logic](./traits/lowering-to-logic.md)
-        - [Goals and clauses](./traits/goals-and-clauses.md)
-        - [Canonical queries](./traits/canonical-queries.md)
-        - [Lowering module in rustc](./traits/lowering-module.md)
+			- [Lowering to logic](./traits/lowering-to-logic.md)
+			- [Goals and clauses](./traits/goals-and-clauses.md)
+			- [Canonical queries](./traits/canonical-queries.md)
+			- [Lowering module in rustc](./traits/lowering-module.md)
     - [Type checking](./type-checking.md)
         - [Method Lookup](./method-lookup.md)
         - [Variance](./variance.md)

src/traits/lowering-module.md

@@ -1 +1,3 @@
 # The lowering module in rustc
+
+This work is ongoing. This section will be filled in once some of it has landed in `rustc`.