Update spec/registry.md

Co-authored-by: Eemeli Aro <[email protected]>

Author: aphillips

spec/registry.md

@@ -943,7 +943,7 @@ as is any `style` option.
 
 When an _operand_ or an _option_ value uses a _variable_ annotated,
 directly or indirectly, by a `:date` _annotation_,
-its resolved value contains the implementation-defined date/time value
+its _resolved value_ contains the implementation-defined date/time value
 of the _operand_ of the annotated _expression_ (with no time value),
 together with the resolved options values.