docs: freshness check for some guides (#13000)

www/apps/book/app/learn/fundamentals/admin/constraints/page.mdx

@@ -4,11 +4,11 @@ export const metadata = {
 
 # {metadata.title}
 
-This chapter lists some constraints of admin widgets and UI routes.
+This chapter lists some development constraints of admin widgets and UI routes.
 
 ## Arrow Functions
 
-Widget and UI route components must be created as arrow functions.
+Widget and UI route components must be created as arrow functions. Otherwise, Medusa doesn't register them correctly.
 
 export const arrowHighlights = [
   ["2", "function", "Don't declare the widget / UI route as a function."],
@@ -31,7 +31,7 @@ const ProductWidget = () => {
 
 ## Widget Zone
 
-A widget zone's value must be wrapped in double or single quotes. It can't be a template literal or a variable.
+A widget zone's value must be wrapped in double or single quotes. It can't be a template literal or a variable. Otherwise, Medusa doesn't register the widget correctly.
 
 export const zoneHighlights = [
   ["3", "`product.details.before`", "Don't specify the value of `zone` as a template literal."],