docs: improvements to create plugin guide (#4285)

* docs: improvements to create plugin guide

* fix link

docs/content/development/services/create-service.mdx

@@ -161,4 +161,4 @@ class MySubscriber {
 
 ## See Also
 
-- [Create a Plugin](../plugins/create.md)
+- [Create a Plugin](../plugins/create.mdx)

docs/content/development/services/overview.mdx

@@ -31,7 +31,7 @@ The service must then be transpiled using the `build` command, which moves them
 
 :::tip
 
-If you're creating a service in a plugin, learn more about the required structure [here](../plugins/create.md#plugin-structure).
+If you're creating a service in a plugin, learn more about the required structure [here](../plugins/create.mdx#plugin-structure).
 
 :::