Sort workspace members (#1760)

This should make it easier to insert new members going forward.

Cargo.toml

@@ -1,30 +1,31 @@
 [workspace]
+# Please keep the workspace members sorted.
 members = [
-  "mdbook-exerciser",
   "mdbook-course",
-  "src/types-and-values",
-  "src/control-flow-basics",
-  "src/tuples-and-arrays",
-  "src/references",
-  "src/user-defined-types",
-  "src/pattern-matching",
-  "src/methods-and-traits",
-  "src/generics",
-  "src/std-types",
-  "src/std-traits",
-  "src/iterators",
-  "src/modules",
-  "src/testing",
-  "src/memory-management",
-  "src/smart-pointers",
-  "src/borrowing",
-  "src/slices-and-lifetimes",
-  "src/error-handling",
-  "src/unsafe-rust",
-  "src/exercises",
+  "mdbook-exerciser",
   "src/bare-metal/useful-crates/allocator-example",
   "src/bare-metal/useful-crates/zerocopy-example",
+  "src/borrowing",
+  "src/control-flow-basics",
+  "src/error-handling",
+  "src/exercises",
   "src/exercises/concurrency/chat-async",
+  "src/generics",
+  "src/iterators",
+  "src/memory-management",
+  "src/methods-and-traits",
+  "src/modules",
+  "src/pattern-matching",
+  "src/references",
+  "src/slices-and-lifetimes",
+  "src/smart-pointers",
+  "src/std-traits",
+  "src/std-types",
+  "src/testing",
+  "src/tuples-and-arrays",
+  "src/types-and-values",
+  "src/unsafe-rust",
+  "src/user-defined-types",
   "third_party/cxx/blobstore",
 ]
 resolver = "2"