ci: update contributing link

Signed-off-by: Alex Wichmann <VisualBean@users.noreply.github.com>

Author: VisualBean

.github/workflows/first-interaction.yml

@@ -15,5 +15,5 @@ jobs:
     - uses: actions/first-interaction@v1
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
-        issue-message: 'Welcome to AsyncAPI.NET. Thank you ${{ github.event.pull_request.user.login }} for reporting your first issue. Please check out our [contributors guide](https://github.com/ByteBardOrg/AsyncAPI.NET/blob/main/CONTRIBUTING.md).'          
-        pr-message: 'Thank you ${{ github.event.pull_request.user.login }} for your first pull request to AsyncAPI.NET repository. Please check out our [contributors guide](https://github.com/ByteBardOrg/AsyncAPI.NET/blob/main/CONTRIBUTING.md).'
+        issue-message: 'Welcome to AsyncAPI.NET. Thank you ${{ github.event.pull_request.user.login }} for reporting your first issue. Please check out our [contributors guide](https://github.com/ByteBardOrg/AsyncAPI.NET/blob/vnext/CONTRIBUTING.md).'          
+        pr-message: 'Thank you ${{ github.event.pull_request.user.login }} for your first pull request to AsyncAPI.NET repository. Please check out our [contributors guide](https://github.com/ByteBardOrg/AsyncAPI.NET/blob/vnext/CONTRIBUTING.md).'