Update RELEASE.md instructions to use GitHub release links.

Author: alexrp

RELEASE.md

@@ -8,10 +8,10 @@ When a new Zig version is released, the process is as follows:
 * Commit the change.
 * Tag a release with
   `git tag v$(ZigVersion).$(ToolsetVersion) -m v$(ZigVersion).$(ToolsetVersion) -s`
-  (e.g. `v0.8.0.1`).
+  (e.g. `v0.13.0.1`).
 * Push the commit and the tag.
-* Edit the draft release on GitHub to add a release notes link, such as
-  [this one](https://ziglang.org/download/0.8.0/release-notes.html).
+* Edit the draft release on GitHub to add a link to the Zig release, such as
+  [this one](https://github.com/ziglang/zig/releases/tag/0.13.0).
 * Publish the release on GitHub.
 
 Fresh NuGet packages will then be built and published by an automatic workflow.