fix dead links

Author: SethTisue

_posts/2019-12-18-road-to-scala-3.md

@@ -89,7 +89,7 @@ By re-compiling an existing library from its TASTy, its class files are regenera
 
 While Scala 3 can generally consume libraries built with Scala 2.13, this does not work for macros. Macro methods defined in 2.13 libraries cannot be used in Scala 3, because the Scala 3 compiler cannot execute the macro at compile-time.
 
-The macro system from Scala 2 is deeply tied to the internals of the Scala 2 compiler and cannot be migrated in a compatible fashion to Scala 3. Instead, Scala 3 ships with a [new macro system](https://dotty.epfl.ch/docs/reference/metaprogramming/toc.html). This means that macro definitions have to be re-written when migrating a codebase to Scala 3. Cross-building is possible by having separate source files for Scala 2 and 3 macro definitions.
+The macro system from Scala 2 is deeply tied to the internals of the Scala 2 compiler and cannot be migrated in a compatible fashion to Scala 3. Instead, Scala 3 ships with a [new macro system](https://docs.scala-lang.org/scala3/reference/metaprogramming.html). This means that macro definitions have to be re-written when migrating a codebase to Scala 3. Cross-building is possible by having separate source files for Scala 2 and 3 macro definitions.
 
 Libraries that define macros can be made available for both Scala 2.13 and Scala 3 by cross-compiling. 
 

_posts/2020-11-06-explicit-term-inference-in-scala-3.md

@@ -202,7 +202,7 @@ This allows you to have more control over imports without relying on instance na
 ### Find out more
 
 You can learn more about `using` / `given` and about the rules of resolution in
-[the documentation](https://dotty.epfl.ch/docs/reference/contextual/motivation.html).
+[the documentation](https://docs.scala-lang.org/scala3/reference/contextual.html).
 
 ### How was this done in Scala 2?