added drone target for new chapter

.drone.yml

@@ -191,6 +191,19 @@ steps:
     ref:
       include:
       - refs/tags/release_temporal*
+- name: release chapter decidability
+  image: plugins/gitea-release
+  settings:
+    base_url: https://git.pranger.xyz
+    api_key:
+      from_secret: gitea_token
+    files:
+    - questionnaire_decidability.pdf
+    - questionnaire_with_solutions_decidability.pdf
+  when:
+    ref:
+      include:
+      - refs/tags/release_decidability*
 trigger:
   event:
     include: