capitalize words for emphasis, per RFC 2119

Author: karenetheridge

jsonschema-core.xml

@@ -3595,9 +3595,9 @@ https://example.com/schemas/common#/$defs/count/minimum
                     behavior is undefined.
                 </t>
                 <t>
-                    Vocabulary authors should provide a meta-schema that validates the
+                    Vocabulary authors SHOULD provide a meta-schema that validates the
                     expected usage of the vocabulary's keywords on their own.  Such meta-schemas
-                    should not forbid additional keywords, and must not forbid any
+                    SHOULD not forbid additional keywords, and MUST not forbid any
                     keywords from the Core vocabulary.
                 </t>
                 <t>