Fix more links

Author: adpi2

_data/scala3-doc-nav-header.yml

@@ -10,7 +10,7 @@
     - title: Macro Tutorial
       url: "/scala3/guides/macros/index.html"
 - title: Migrate
-  url: "https://scalacenter.github.io/scala-3-migration-guide"
+  url: "/scala3/guides/migration/compatibility-intro.html"
 - title: Reference
   url: "https://dotty.epfl.ch/docs/reference/overview.html"
 - title: API

_ja/scala3/contribute-to-docs.md

@@ -42,9 +42,8 @@ Scala 3 の高品質なドキュメンテーションを作るためのいくつ
 ## Migration Guide
 [Scala 3 Migration Guide](/scala3/guides/migration/compatibility-intro.html) は Scala 2 と Scala 3 の互換性、移行に役立つツールの紹介、そして詳しい移行のガイドを含んだ包括的なドキュメントである。
 
-- [Contribution Overview](https://scalacenter.github.io/scala-3-migration-guide/docs/contributing.html)
-- [Source](https://github.com/scalacenter/scala-3-migration-guide)
-- [Issues](https://github.com/scalacenter/scala-3-migration-guide/issues)
+- [Source](https://github.com/scala/docs.scala-lang/tree/master/_overviews/scala3-migration)
+- [Issues](https://github.com/scalacenter/docs.scala-lang/issues)
 
 
 ## Scala 3 Language Reference

_ja/scala3/guides.md

@@ -8,7 +8,7 @@ scala3: true
 guides:
   - title: "Scala 2 から Scala 3 への移行"
     icon: suitcase
-    url: "https://scalacenter.github.io/scala-3-migration-guide"
+    url: "/scala3/guides/migration/compatibility-intro.html"
     description: "Scala 3 との互換性と移行について知っておくべきことすべて"
   - title: マクロ
     by: Nicolas Stucki

scala3/contribute-to-docs.md

@@ -42,10 +42,8 @@ The [Scala 3 Migration Guide](/scala3/guides/migration/compatibility-intro.html)
 contains an comprehensive overview over compatibility between Scala 2 and Scala 3,
 a tour presenting the migration tools, and detailed migration guides.
 
-- [Contribution Overview](https://scalacenter.github.io/scala-3-migration-guide/docs/contributing.html)
-- [Source](https://github.com/scalacenter/scala-3-migration-guide)
-- [Issues](https://github.com/scalacenter/scala-3-migration-guide/issues)
-
+- [Source](https://github.com/scala/docs.scala-lang/tree/master/_overviews/scala3-migration)
+- [Issues](https://github.com/scalacenter/docs.scala-lang/issues)
 
 ## Scala 3 Language Reference
 The [Dotty reference](https://dotty.epfl.ch/docs/reference/overview.html) will evolve into the Scala 3 language, containing  a formal presentation and detailed technical information about the various features of the language.