ci: add new issues to backlog project

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

.github/workflows/add-issues-to-backlog.yml

@@ -0,0 +1,16 @@
+name: Add issues to backlog project
+
+on:
+  issues:
+    types:
+      - opened
+
+jobs:
+  add-to-project:
+    name: Add issue to project
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/add-to-project@v0.0.3
+        with:
+          project-url: https://github.com/orgs/dagger/projects/2
+          github-token: ${{ secrets.ADD_TO_PROJECT_PAT }}