add changeset

Author: silesky

.changeset/heavy-taxis-suffer.md

@@ -0,0 +1,23 @@
+---
+'@segment/analytics-next': minor
+---
+Add new `additionalHeaders` setting, along with `fetchPriority`.
+
+```ts
+analytics.load("<YOUR_WRITE_KEY>",
+  {
+    integrations: {
+      'Segment.io': {
+        deliveryStrategy: {
+          strategy: "standard" // also works for 'batching'
+          config: {
+            additionalHeaders: { 'x-api-key': 'foo' } or () => {...}
+            fetchPriority: 'low' | 'high', // new setting
+          },
+        },
+      },
+    },
+  }
+)
+
+```