doc/ref/spec.md: fix spec bug and broken link
Change-Id: Ibb578957275ea26c73688d00d291c61e391622d7
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/7162
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/doc/ref/spec.md b/doc/ref/spec.md
index ca9df9f..8be1270 100644
--- a/doc/ref/spec.md
+++ b/doc/ref/spec.md
@@ -1243,8 +1243,8 @@
Recursively closing a struct is equivalent to adding `..._|_` to its its root
and any of its substructures that are not defined for all fields.
-Syntactically, structs are recursively closed explicitly with
-the `close` builtin or implicitly by [definitions](#Definitions).
+Syntactically, structs are closed explicitly with the `close` builtin or
+implicitly and recursively by [definitions](#definitions-and-hidden-fields).
```
