docs: update 'part' keyword link

Current link is no longer available, change to the new available link

docs/src/content/docs/tutorials/flutter-weather.mdx

@@ -184,7 +184,7 @@ In order for code generation to work, we need to annotate our code using the fol
 For each file we also need to:
 
 - Import `json_annotation`
-- Include the generated code using the [part](https://dart.dev/guides/libraries/create-library-packages#organizing-a-library-package) keyword
+- Include the generated code using the [part](https://dart.dev/tools/pub/create-packages#organizing-a-package) keyword
 - Include `fromJson` methods for deserialization
 
 #### Location Model