docs: replace fastify.io links with fastify.dev

plugins/README.md

@@ -12,5 +12,5 @@ that will then be used in the rest of your application.
 Check out:
 
 * [The hitchhiker's guide to plugins](https://github.com/fastify/fastify/blob/master/docs/Plugins-Guide.md)
-* [Fastify decorators](https://www.fastify.io/docs/latest/Decorators/).
-* [Fastify lifecycle](https://www.fastify.io/docs/latest/Lifecycle/).
+* [Fastify decorators](https://fastify.dev/docs/latest/Decorators/).
+* [Fastify lifecycle](https://fastify.dev/docs/latest/Lifecycle/).

services/README.md

@@ -7,7 +7,7 @@ to independently deploy some of those.
 In this folder you should define all the services that define the routes
 of your web application.
 Each service is a [Fastify
-plugin](https://www.fastify.io/docs/latest/Plugins/), it is
+plugin](https://fastify.dev/docs/latest/Plugins/), it is
 encapsulated (it can have its own independent plugins) and it is
 typically stored in a file; be careful to group your routes logically,
 e.g. all `/users` routes in a `users.js` file. We have added
@@ -21,4 +21,4 @@ and eventually extract them.
 
 If you need to share functionality between services, place that
 functionality into the `plugins` folder, and share it via
-[decorators](https://www.fastify.io/docs/latest/Decorators/).
+[decorators](https://fastify.dev/docs/latest/Decorators/).