Fix heading text

act-rules-format/act-rules-format.bs

@@ -177,7 +177,7 @@ Each [=accessibility requirement=] in the mapping <em class="rfc2119">must</em>
 ### Outcome Mapping ### {#outcome-mapping}
 For each conformance requirement in the mapping, an ACT Rule <em class="rfc2119">must</em> indicate what the [=outcomes=] of the rule mean for satisfying an accessibility requirement for that [=test subject=]. 
 
-#### Conformance Requirements ### {#conformance-requirements}
+#### Conformance Requirements #### {#conformance-requirements}
 
 When a rule is designed to test a specific accessibility requirement, the accessibility requirement is mapped as a Conformance Requirement when both of the following conditions are true: