chore(workflow): link to minor branch changelog for pre-releases [ci skip]

Author: yyx990803

.github/workflows/release-tag.yml

@@ -24,4 +24,5 @@ jobs:
         with:
           tag_name: ${{ github.ref }}
           body: |
-            Please refer to [CHANGELOG.md](https://github.com/vuejs/core/blob/main/CHANGELOG.md) for details.
+            For stable releases, please refer to [CHANGELOG.md](https://github.com/vuejs/core/blob/main/CHANGELOG.md) for details.
+            For pre-releases, please refer to [CHANGELOG.md](https://github.com/vuejs/core/blob/minor/CHANGELOG.md) of the `minor` branch.