Add PR template foldable end sections

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: MariusStorhaug

.github/pull_request_template.md

@@ -0,0 +1,29 @@
+<!-- Lead with user-facing outcome in one concise paragraph. -->
+
+## New: <capability>
+
+<!-- User-facing additions. -->
+
+## Changed: <behavior>
+
+<!-- User-facing behavior changes. -->
+
+## Fixed: <problem>
+
+<!-- User-facing fixes. Remove unused sections before marking ready. -->
+
+---
+
+<details>
+<summary>Technical details</summary>
+
+<!-- Internal implementation notes for reviewers/maintainers. -->
+
+</details>
+
+<details>
+<summary>Relevant issues (or links)</summary>
+
+<!-- Use fully qualified references, e.g. Fixes Owner/Repo#123 -->
+
+</details>