add xrefs for constraints index page (neo4j#1311)

Author: JPryce-Aklundh

modules/ROOT/pages/constraints/index.adoc

@@ -5,10 +5,10 @@ include::https://raw.githubusercontent.com/neo4j-graphacademy/courses/main/ascii
 Neo4j offers several constraints to ensure the quality and integrity of data in a graph.
 The following constraints are available in Neo4j:
 
-* *Property uniqueness constraints* ensure that the combined property values are unique for all nodes with a specific label or all relationships with a specific type. 
-* *Property existence constraints* ensure that a property exists either for all nodes with a specific label or for all relationships with a specific type. label:enterprise-edition[]
-* *Property type constraints* ensure that a property has the required property type for all nodes with a specific label or for all relationships with a specific type. label:new[Introduced in 5.9] label:enterprise-edition[]
-* *Key constraints* ensure that all properties exist and that the combined property values are unique for all nodes with a specific label or all relationships with a specific type.label:enterprise-edition[]
+* xref:constraints/managing-constraints.adoc#create-property-uniqueness-constraints[Property uniqueness constraints]: ensure that the combined property values are unique for all nodes with a specific label or all relationships with a specific type. 
+* xref:constraints/managing-constraints.adoc#create-property-existence-constraints[Property existence constraints]: ensure that a property exists either for all nodes with a specific label or for all relationships with a specific type. label:enterprise-edition[]
+* xref:constraints/managing-constraints.adoc#create-property-type-constraints[Property type constraints]: ensure that a property has the required property type for all nodes with a specific label or for all relationships with a specific type. label:new[Introduced in 5.9] label:enterprise-edition[]
+* xref:constraints/managing-constraints.adoc#create-key-constraints[Key constraints]: ensure that all properties exist and that the combined property values are unique for all nodes with a specific label or all relationships with a specific type.label:enterprise-edition[]
 
 To learn more about creating, listing, and dropping these constraints, as well as information about index-backed constraints, constraint creation failures and data violation scenarios, and more, see xref:constraints/managing-constraints.adoc[].