docs: revise commerce modules overview pages (#10738)

* revise API Key Module overview

* revise auth module

* support ref sidebar items

* remove examples

* revise cart module

* revise currency

* revise customer module

* revise fulfillment module

* revise inventory module

* revise order module

* revise payment

* revise pricing module

* revise product module

* revise promotion module

* revise region module

* revise sales channel module

* revise stock location module

* revise store module

* revise tax module

* revise user module

* lint content + fix snippets

www/packages/docs-ui/src/components/MDXComponents/index.tsx

@@ -120,3 +120,5 @@ export const MDXComponents: MDXComponentsType = {
     return <ZoomImg {...rest} />
   },
 }
+
+export const Hr = MDXComponents["hr"] as () => React.JSX.Element