docs: small fixes and improvements to text (#14385)

www/apps/book/app/learn/fundamentals/api-routes/override/page.mdx

@@ -8,7 +8,7 @@ export const metadata = {
 
 In this chapter, you'll learn the approach recommended when you need to override an existing API route in Medusa.
 
-## Approaches to Consider Before Overriding API Routes
+## Approaches to Consider Instead of Overriding API Routes
 
 While building customizations in your Medusa application, you may need to make changes to existing API routes for your business use case.