docs: TSDoc + reference of fulfillment service (#5761)

www/apps/docs/content/references/services/classes/Region.mdx

@@ -8,14 +8,14 @@ import ParameterTypes from "@site/src/components/ParameterTypes"
 
 A region holds settings specific to a geographical location, including the currency, tax rates, and fulfillment and payment providers. A Region can consist of multiple countries to accomodate common shopping settings across countries.
 
-## Constructors
-
-#### constructor
+## constructor
 
 `**new Region**()`
 
 A region holds settings specific to a geographical location, including the currency, tax rates, and fulfillment and payment providers. A Region can consist of multiple countries to accomodate common shopping settings across countries.
 
+___
+
 ## Properties
 
 <ParameterTypes parameters={[
@@ -193,13 +193,15 @@ A region holds settings specific to a geographical location, including the curre
   }
 ]} />
 
+___
+
 ## Methods
 
-#### beforeInsert
+### beforeInsert
 
 `Private **beforeInsert**(): void`
 
-##### Returns
+#### Returns
 
 `void`