docs: fix outdated links (#10040)

www/apps/book/app/learn/customization/extend-models/define-link/page.mdx

@@ -18,7 +18,7 @@ This chapter covers how to define a link between the `Brand` and `Product`data m
   items={[
     {
       text: "Brand Module having a Brand data model",
-      link: "/customization/custom-features/module"
+      link: "/learn/customization/custom-features/module"
     }
   ]}
 />

www/apps/book/app/learn/customization/extend-models/extend-create-product/page.mdx

@@ -26,11 +26,11 @@ It's useful when you want to pass custom data, such as the brand ID, then perfor
   items={[
     {
       text: "Brand Module",
-      link: "/customization/custom-features/module"
+      link: "/learn/customization/custom-features/module"
     },
     {
       text: "Defined link between the Brand and Product data models.",
-      link: "/customization/extend-models/define-link"
+      link: "/learn/customization/extend-models/define-link"
     }
   ]}
 />

www/apps/book/app/learn/customization/extend-models/query-linked-records/page.mdx

@@ -24,11 +24,11 @@ Query is a utility that retrieves data across modules and their links. It’s re
   items={[
     {
       text: "Brand Module",
-      link: "/customization/custom-features/module"
+      link: "/learn/customization/custom-features/module"
     },
     {
       text: "Defined link between the Brand and Product data models.",
-      link: "/customization/extend-models/define-link"
+      link: "/learn/customization/extend-models/define-link"
     }
   ]}
 />