Add platform field, rework some points (#5660)

.github/ISSUE_TEMPLATE/announcement.yml

@@ -26,6 +26,12 @@ body:
       placeholder: Description of who might be impacted by this change
     validations:
       required: true
+  - type: checkboxes
+    attributes:
+      label: Platforms affected
+      options:
+        - label: Azure DevOps
+        - label: GitHub Actions
   - type: checkboxes
     attributes:
       label: Virtual environments affected
@@ -38,8 +44,6 @@ body:
         - label: macOS 12
         - label: Windows Server 2019
         - label: Windows Server 2022
-    validations:
-      required: true
   - type: textarea
     attributes:
       label: Mitigation ways