codeberg: redirect to river-classic in issue template

 .gitea/issue_template/bug.yml | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/.gitea/issue_template/bug.yml b/.gitea/issue_template/bug.yml
index 43fc383..089b4c9 100644
--- a/.gitea/issue_template/bug.yml
+++ b/.gitea/issue_template/bug.yml
@@ -14,8 +14,11 @@ body:
     id: version
     attributes:
       label: river Version
-      description: "The output of `river -version`"
-      placeholder: "0.3.0-dev.293+b77b42f"
+      description: |
+        The output of `river -version`.
+        If the version starts with 0.3, please open an issue on the
+        [river-classic](https://codeberg.org/river/river-classic/) repository instead.
+      placeholder: "0.4.0-dev.247+a050b8b"
     validations:
       required: true
   - type: textarea