Update constraints.rst
Fix typos
@@ -8,8 +8,8 @@ Constraints
This section assumes a basic understanding of EdgeQL.
-Constraints gives users fine-grained control over which data is considered
-valid. The can be defined on :ref:`properties <ref_datamodel_props>`,
+Constraints give users fine-grained control over which data is considered
+valid. They can be defined on :ref:`properties <ref_datamodel_props>`,
:ref:`links <ref_datamodel_links>`, :ref:`object types
<ref_datamodel_object_types>`, and :ref:`custom scalars
<ref_datamodel_links>`.
