Add identifier syntax to attributes.type_system

Author: chorman0773

src/attributes/type_system.md

@@ -1,16 +1,26 @@
 # Type system attributes
 
+r[attributes.type-system]
+
 The following [attributes] are used for changing how a type can be used.
 
 ## The `non_exhaustive` attribute
 
+r[attributes.type-system.non_exhaustive]
+
+
+r[attributes.type-system.non_exhaustive.general]
 The *`non_exhaustive` attribute* indicates that a type or variant may have
-more fields or variants added in the future. It can be applied to
-[`struct`s][struct], [`enum`s][enum], and `enum` variants.
+more fields or variants added in the future. 
+
+r[attributes.type-system.non_exhaustive.restriction]
+It can be applied to [`struct`s][struct], [`enum`s][enum], and `enum` variants.
 
+r[attributes.type-system.non_exhaustive.syntax]
 The `non_exhaustive` attribute uses the [_MetaWord_] syntax and thus does not
 take any inputs.
 
+r[attributes.type-system.non_exhaustive.same-crate]
 Within the defining crate, `non_exhaustive` has no effect.
 
 ```rust
@@ -65,9 +75,11 @@ match message {
 }
 ```
 
+r[attributes.type-system.non_exhaustive.external-crate]
 Outside of the defining crate, types annotated with `non_exhaustive` have limitations that
 preserve backwards compatibility when new fields or variants are added.
 
+r[attributes.type-system.non_exhaustive.construction]
 Non-exhaustive types cannot be constructed outside of the defining crate:
 
 - Non-exhaustive variants ([`struct`][struct] or [`enum` variant][enum]) cannot be constructed
@@ -119,6 +131,7 @@ let message = Message::Reaction(0);
 let message = Message::Quit;
 ```
 
+r[attributes.type-system.non_exhaustive.match]
 There are limitations when matching on non-exhaustive types outside of the defining crate:
 
 - When pattern matching on a non-exhaustive variant ([`struct`][struct] or [`enum` variant][enum]),