docs: Add release note for changes to 'headers' field

Signed-off-by: Stephen Finucane <stephen@that.guru>

diff --git a/releasenotes/notes/show-duplicated-headers-ee218a4cc1fc61f5.yaml b/releasenotes/notes/show-duplicated-headers-ee218a4cc1fc61f5.yaml
new file mode 100644 (file)
index 0000000..dc75b91
--- /dev/null
+++ b/releasenotes/notes/show-duplicated-headers-ee218a4cc1fc61f5.yaml
@@ -0,0 +1,6 @@
+---
+api:
+  - |
+    Messages headers that use the same key, such as ``Received:`` are now
+    combined into a list. Previously only one of the values would be output.
+    This affects the ``/covers`` and ``/patches`` endpoints.