Update fedramp-external-constraints.xml

Co-authored-by: Gabeblis <[email protected]>

src/validations/constraints/fedramp-external-constraints.xml

@@ -488,7 +488,7 @@
             <expect id="party-has-name" target="." test="exists(name)" level="ERROR">
                 <formal-name>Party Has a Name</formal-name>
                 <prop namespace="https://docs.oasis-open.org/sarif/sarif/v2.1.0" name="help-url" value="https://automate.fedramp.gov/documentation/general-concepts/oscal-metadata/#working-with-party-assemblies"/>
-                <message>Every FedRAMP document must define a party with a name.</message>
+                <message>Every FedRAMP document MUST define a party with a name.</message>
             </expect>
         </constraints>
     </context>